Imported Upstream version 1.0.25upstream/1.0.25

1 files changed, 1422 insertions, 0 deletions

diff --git a/backend/pieusb.c b/backend/pieusb.c
new file mode 100644
index 0000000..4b07304
--- /dev/null
+++ b/backend/pieusb.c
@@ -0,0 +1,1422 @@
+/* sane - Scanner Access Now Easy.
+
+   pieusb.c
+
+   Copyright (C) 2012-2015 Jan Vleeshouwers, Michael Rickmann, Klaus Kaempf
+
+   This file is part of the SANE package.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.  */
+
+/* =========================================================================
+ *
+ * SANE interface to three Reflecta USB scanners with USB-id 0x05e3/0x0145:
+ * - Reflecta CrystalScan 7200 (model id 0x30)
+ * - Reflecta ProScan 7200 (model id 0x36)
+ * - Reflecta 6000 Multiple Slide Scanner (model id 0x3A)
+ *
+ * ========================================================================= */
+
+#define DEBUG_NOT_STATIC
+/* --------------------------------------------------------------------------
+ *
+ * INCLUDES
+ *
+ * --------------------------------------------------------------------------*/
+
+#include "../include/sane/config.h"
+/* Standard includes for various utiliy functions */
+#include <stdio.h> /* for FILE */
+#include <string.h> /* for strlen */
+#include <stdlib.h> /* for NULL */
+#include <stdint.h>
+#include <math.h>
+
+/* Configuration defines */
+#include "../include/sane/config.h"
+
+/* SANE includes */
+#include "../include/sane/sane.h"
+#include "../include/sane/saneopts.h"
+#include "../include/sane/sanei_usb.h"
+#include "../include/sane/sanei_config.h"
+
+/* Backend includes */
+#define BACKEND_NAME pieusb
+#include "../include/sane/sanei_backend.h"
+#include "pieusb.h"
+#include "pieusb_specific.h"
+
+#define CAN_DO_4_CHANNEL_TIFF
+
+#ifdef CAN_DO_4_CHANNEL_TIFF
+extern void write_tiff_rgbi_header (FILE *fptr, int width, int height, int depth, int resolution, const char *icc_profile);
+#endif
+
+/* --------------------------------------------------------------------------
+ *
+ * DEFINES
+ *
+ * --------------------------------------------------------------------------*/
+
+/* Build number of this backend */
+#define BUILD 1
+
+/* Configuration filename */
+#define PIEUSB_CONFIG_FILE "pieusb.conf"
+
+/* Debug error levels */
+#define DBG_error        1      /* errors */
+#define DBG_warning      3      /* warnings */
+#define DBG_info         5      /* information */
+#define DBG_info_sane    7      /* information sane interface level */
+#define DBG_inquiry      8      /* inquiry data */
+#define DBG_info_proc    9      /* information pieusb backend functions */
+#define DBG_info_scan   11      /* information scanner commands */
+#define DBG_info_usb    13      /* information usb level functions */
+
+/* --------------------------------------------------------------------------
+ *
+ * SUPPORTED DEVICES SPECIFICS
+ *
+ * --------------------------------------------------------------------------*/
+
+struct Pieusb_USB_Device_Entry* pieusb_supported_usb_device_list = NULL;
+struct Pieusb_USB_Device_Entry pieusb_supported_usb_device; /* for searching */
+
+/* --------------------------------------------------------------------------
+ *
+ * LISTS OF ACTIVE DEVICE DEFINITIONS AND SCANNERS
+ *
+ * --------------------------------------------------------------------------*/
+
+Pieusb_Device_Definition *pieusb_definition_list_head = NULL;
+static Pieusb_Scanner *first_handle = NULL;
+static const SANE_Device **devlist = NULL;
+
+/* --------------------------------------------------------------------------
+ *
+ * SANE INTERFACE
+ *
+ * --------------------------------------------------------------------------*/
+
+/**
+ * Initializes the debugging system, the USB system, the version code and
+ * 'attaches' available scanners, i.e. creates device definitions for all
+ * scanner devices found.
+ *
+ * @param version_code
+ * @param authorize
+ * @return SANE_STATUS_GOOD
+ */
+SANE_Status
+sane_init (SANE_Int * version_code, SANE_Auth_Callback __sane_unused__ authorize)
+{
+    FILE *fp;
+    char config_line[PATH_MAX];
+    SANE_Word vendor_id;
+    SANE_Word product_id;
+    SANE_Word model_number;
+    SANE_Status status;
+    int i;
+
+    /* Initialize debug logging */
+    DBG_INIT ();
+
+    DBG (DBG_info_sane, "sane_init() build %d\n", BUILD);
+
+    /* Set version code to current major, minor and build number */
+    /* TODO: use V_MINOR instead or SANE_CURRENT_MINOR? If so, why?  */
+    if (version_code)
+        *version_code = SANE_VERSION_CODE (SANE_CURRENT_MAJOR, SANE_CURRENT_MINOR, BUILD);
+
+    /* Initialize usb */
+    sanei_usb_init ();
+    sanei_usb_set_timeout (30 * 1000); /* 30 sec timeout */
+
+    /* There are currently 3 scanners hardcoded into this backend, see below.
+     * The config file may add other scanners using a line like
+     * usb 0x1234 0x5678 0x9A
+     * where the first two hex numbers are vendor and product id, and the last
+     * number is the model number. Unfortunately, this is not according to the
+     * config file standard. Anyone any suggestions? */
+
+    /* Create default list */
+    pieusb_supported_usb_device_list = calloc (4, sizeof(struct Pieusb_USB_Device_Entry));
+    if (pieusb_supported_usb_device_list == NULL)
+      return SANE_STATUS_NO_MEM;
+    /* Reflecta CrystalScan 7200, model number 0x30 */
+    pieusb_supported_usb_device_list[0].vendor = 0x05e3;
+    pieusb_supported_usb_device_list[0].product = 0x0145;
+    pieusb_supported_usb_device_list[0].model = 0x30;
+    /* Reflecta ProScan 7200, model number 0x36 */
+    pieusb_supported_usb_device_list[1].vendor = 0x05e3;
+    pieusb_supported_usb_device_list[1].product = 0x0145;
+    pieusb_supported_usb_device_list[1].model = 0x36;
+    /* Reflecta 6000 Multiple Slide Scanner */
+    pieusb_supported_usb_device_list[2].vendor = 0x05e3;
+    pieusb_supported_usb_device_list[2].product = 0x0142;
+    pieusb_supported_usb_device_list[2].model = 0x3a;
+    /* end of list */
+    pieusb_supported_usb_device_list[3].vendor = 0;
+    pieusb_supported_usb_device_list[3].product = 0;
+    pieusb_supported_usb_device_list[3].model = 0;
+
+    /* Add entries from config file */
+    fp = sanei_config_open (PIEUSB_CONFIG_FILE);
+    if (!fp) {
+        DBG (DBG_info_sane, "sane_init() did not find a config file, using default list of supported devices\n");
+    } else {
+        while (sanei_config_read (config_line, sizeof (config_line), fp)) {
+            /* Ignore line comments and empty lines */
+            if (config_line[0] == '#') continue;
+            if (strlen (config_line) == 0) continue;
+            /* Ignore lines which do not begin with 'usb ' */
+            if (strncmp (config_line, "usb ", 4) != 0) continue;
+            /* Parse vendor-id, product-id and model number and add to list */
+            DBG (DBG_info_sane, "sane_init() config file parsing %s\n", config_line);
+            status = sanei_pieusb_parse_config_line(config_line, &vendor_id, &product_id, &model_number);
+            if (status == SANE_STATUS_GOOD) {
+                DBG (DBG_info_sane, "sane_init() config file lists device %04x %04x %02x\n",vendor_id, product_id, model_number);
+                if (!sanei_pieusb_supported_device_list_contains(vendor_id, product_id, model_number)) {
+                    DBG (DBG_info_sane, "sane_init() adding device %04x %04x %02x\n",vendor_id, product_id, model_number);
+                    sanei_pieusb_supported_device_list_add(vendor_id, product_id, model_number);
+                } else {
+                    DBG (DBG_info_sane, "sane_init() list already contains %04x %04x %02x\n", vendor_id, product_id, model_number);
+                }
+            } else {
+                DBG (DBG_info_sane, "sane_init() config file parsing %s: error\n", config_line);
+            }
+	}
+        fclose (fp);
+    }
+
+    /* Loop through supported device list */
+    i = 0;
+    while (pieusb_supported_usb_device_list[i].vendor != 0) {
+        /* Check if the supported device is present. If so, create a device
+         * definition structure for it.
+         * The variable pieusb_supported_usb_device is set to current values,
+         * which are used in the callback. */
+        pieusb_supported_usb_device.vendor = pieusb_supported_usb_device_list[i].vendor;
+        pieusb_supported_usb_device.product = pieusb_supported_usb_device_list[i].product;
+        pieusb_supported_usb_device.model = pieusb_supported_usb_device_list[i].model;
+        pieusb_supported_usb_device.device_number = -1; /* No device number (yet) */
+        DBG( DBG_info_sane, "sane_init() looking for Reflecta scanner %04x %04x model %02x\n", pieusb_supported_usb_device.vendor, pieusb_supported_usb_device.product, pieusb_supported_usb_device.model);
+        sanei_usb_find_devices (pieusb_supported_usb_device.vendor, pieusb_supported_usb_device.product, sanei_pieusb_find_device_callback);
+        i++;
+    }
+    return SANE_STATUS_GOOD;
+}
+
+/**
+ * Backend exit.
+ * Clean up allocated memory.
+ */
+void
+sane_exit (void)
+{
+    Pieusb_Device_Definition *dev, *next;
+
+    DBG (DBG_info_sane, "sane_exit()\n");
+
+    for (dev = pieusb_definition_list_head; dev; dev = next) {
+        next = dev->next;
+        free((void *)dev->sane.name);
+        free((void *)dev->sane.vendor);
+        free((void *)dev->sane.model);
+        free (dev->version);
+        free (dev);
+    }
+    pieusb_definition_list_head = NULL;
+
+    if (devlist) {
+        free (devlist);
+        devlist = NULL;
+    }
+}
+
+/**
+ * Create a SANE device list from the device list generated by sane_init().
+ *
+ * @param device_list List of SANE_Device elements
+ * @param local_only If true, disregard network scanners. Not applicable for USB scanners.
+ * @return SANE_STATUS_GOOD, or SANE_STATUS_NO_MEM if the list cannot be allocated
+ */
+SANE_Status
+sane_get_devices (const SANE_Device *** device_list, SANE_Bool __sane_unused__ local_only)
+{
+    Pieusb_Device_Definition *dev;
+    int i;
+
+    DBG (DBG_info_sane, "sane_get_devices\n");
+
+    /* Create SANE_DEVICE list from device list created in sane_init() */
+    i = 0;
+    for (dev = pieusb_definition_list_head; dev; dev = dev->next) {
+        i++;
+    }
+    if (devlist) {
+        free (devlist);
+    }
+    devlist = malloc ((i + 1) * sizeof (devlist[0]));
+    if (!devlist) {
+        return SANE_STATUS_NO_MEM;
+    }
+    i = 0;
+    for (dev = pieusb_definition_list_head; dev; dev = dev->next) {
+        devlist[i++] = &dev->sane;
+    }
+    devlist[i] = NULL;
+    *device_list = devlist;
+    return SANE_STATUS_GOOD;
+}
+
+/**
+ * Open the scanner with the given devicename and return a handle to it, which
+ * is a pointer to a Pieusb_Scanner struct. The handle will be an input to
+ * a couple of other functions of the SANE interface.
+ *
+ * @param devicename Name of the device, corresponds to SANE_Device.name
+ * @param handle handle to scanner (pointer to a Pieusb_Scanner struct)
+ * @return SANE_STATUS_GOOD if the device has been opened
+ */
+SANE_Status
+sane_open (SANE_String_Const devicename, SANE_Handle * handle)
+{
+    Pieusb_Device_Definition *dev;
+    SANE_Status status;
+    Pieusb_Scanner *scanner, *s;
+
+    DBG (DBG_info_sane, "sane_open(%s)\n", devicename);
+
+    /* Search for devicename */
+    if (devicename[0]) {
+        for (dev = pieusb_definition_list_head; dev; dev = dev->next) {
+	  if (strcmp (dev->sane.name, devicename) == 0) {
+	      break;
+	  }
+        }
+        if (!dev) {
+            /* Is it a valid USB device? */
+            SANE_Word vendor;
+            SANE_Word product;
+            int i = 0;
+
+            status = sanei_usb_get_vendor_product_byname (devicename, &vendor, &product);
+            if (status != SANE_STATUS_GOOD) {
+                DBG (DBG_error, "sane_open: sanei_usb_get_vendor_product_byname failed %s\n", devicename);
+                return status;
+            }
+            /* Get vendor-product-model & verify that is is supported */
+            /* Loop through supported device list */
+            while (pieusb_supported_usb_device_list[i].vendor != 0) {
+                /* Check if vendor and product match */
+                if (pieusb_supported_usb_device_list[i].vendor == vendor
+                        && pieusb_supported_usb_device_list[i].product == product) {
+                    /* Check if a supported device is present
+                     * If so, create a device definition structure for it. */
+                    /* Set pieusb_supported_usb_device to current values: these are used in callback */
+                    pieusb_supported_usb_device.vendor = vendor;
+                    pieusb_supported_usb_device.product = product;
+                    pieusb_supported_usb_device.model = pieusb_supported_usb_device_list[i].model;
+                    pieusb_supported_usb_device.device_number = -1;
+                    sanei_usb_find_devices (vendor, product, sanei_pieusb_find_device_callback);
+                    if (pieusb_supported_usb_device.device_number == -1) {
+                        /* Did not succeed in opening the USB device, which is an error.
+                         * This error is not caught by sanei_usb_find_devices(), so handle
+                         * it here. */
+                        DBG (DBG_error, "sane_open: sanei_usb_find_devices did not open device %s\n", devicename);
+                        return SANE_STATUS_INVAL;
+                    }
+                }
+                i++;
+            }
+            /* Now rescan the device list to see if it is present */
+            for (dev = pieusb_definition_list_head; dev; dev = dev->next) {
+              if (strcmp (dev->sane.name, devicename) == 0) {
+                  break;
+              }
+            }
+	}
+    } else {
+        /* empty devicename -> use first device */
+        dev = pieusb_definition_list_head;
+    }
+    /* If no device found, return error */
+    if (!dev) {
+        return SANE_STATUS_INVAL;
+    }
+
+    /* Now create a scanner structure to return */
+
+    /* Check if we are not opening the same scanner again. */
+    for (s = first_handle; s; s = s->next) {
+        if (s->device->sane.name == devicename) {
+            *handle = s;
+            return SANE_STATUS_GOOD;
+        }
+    }
+
+    /* Create a new scanner instance */
+    scanner = malloc (sizeof (*scanner));
+    if (!scanner) {
+        return SANE_STATUS_NO_MEM;
+    }
+    memset (scanner, 0, sizeof (*scanner));
+    scanner->device = dev;
+    sanei_usb_open (dev->sane.name, &scanner->device_number);
+    scanner->cancel_request = 0;
+    scanner->shading_data_present = SANE_FALSE;
+    /* Options and buffers */
+    (void)sanei_pieusb_init_options (scanner);
+
+    /* wait for warmup */
+    status = sanei_pieusb_wait_ready (scanner, 0);
+    if (status != SANE_STATUS_GOOD) {
+      sanei_usb_close(scanner->device_number);
+      free (scanner);
+      DBG (DBG_error, "sane_open: scanner not ready\n");
+      return status;
+    }
+
+    /* First time settings */
+    /* ? */
+    /* Insert newly opened handle into list of open handles: */
+    scanner->next = first_handle;
+    first_handle = scanner;
+
+    *handle = scanner;
+    return SANE_STATUS_GOOD;
+}
+
+/**
+ * Close the scanner and remove the scanner from the list of active scanners.
+ *
+ * @param handle Scanner handle
+ */
+void
+sane_close (SANE_Handle handle)
+{
+    Pieusb_Scanner *prev, *scanner;
+    SANE_Int k;
+
+    DBG (DBG_info_sane, "sane_close()\n");
+
+    /* Find handle in list of open handles: */
+    prev = 0;
+    for (scanner = first_handle; scanner; scanner = scanner->next)  {
+        if (scanner == handle) {
+            break;
+        }
+        prev = scanner;
+    }
+    /* Not a handle we know about. This may happen since all different backend
+     * scanner instances are all cast to SANE_Handle (a void pointer) */
+    if (!scanner) {
+        DBG (DBG_error, "sane_close(): invalid handle %p\n", handle);
+        return;
+    }
+
+    /* Stop scan if still scanning */
+    if (scanner->scanning) {
+        sanei_pieusb_on_cancel(scanner);
+    }
+
+    /* USB scanners may be still open here */
+    if (scanner->device_number >= 0) {
+        sanei_usb_reset (scanner->device_number);
+        sanei_usb_close (scanner->device_number);
+    }
+    /* Remove handle from list */
+    if (prev) {
+        prev->next = scanner->next;
+    } else {
+        first_handle = scanner->next;
+    }
+
+    /* Free scanner related allocated memory and the scanner itself */
+    /*TODO: check if complete */
+    if (scanner->buffer.data) sanei_pieusb_buffer_delete(&scanner->buffer);
+    free (scanner->ccd_mask);
+    for (k=0; k<4; k++) free (scanner->shading_ref[k]);
+    free (scanner->val[OPT_MODE].s);
+    free (scanner->val[OPT_HALFTONE_PATTERN].s);
+    free (scanner);
+}
+
+/**
+ * Get option descriptor. Return the option descriptor with the given index
+ *
+ * @param handle Scanner handle
+ * @param option Index of option descriptor to return
+ * @return The option descriptor
+ */
+const SANE_Option_Descriptor *
+sane_get_option_descriptor (SANE_Handle handle, SANE_Int option)
+{
+    Pieusb_Scanner *scanner = handle;
+
+    DBG (DBG_info_proc, "sane_get_option_descriptor() option=%d\n", option);
+
+    if ((unsigned) option >= NUM_OPTIONS)
+    {
+      return 0;
+    }
+
+    return scanner->opt + option;
+}
+
+/**
+ * Set or inquire the current value of option number 'option' of the device
+ * represented by the given handle.
+ *
+ * @param handle Scanner handle
+ * @param option Index of option to set or get
+ * @param action Determines if the option value is read or set
+ * @param val Pointer to value to set or get
+ * @param info About set result. May be NULL.
+ * @return SANE_STATUS_GOOD, or SANE_STATUS_INVAL if a parameter cannot be set
+ */
+SANE_Status
+sane_control_option (SANE_Handle handle, SANE_Int option, SANE_Action action,
+		     void *val, SANE_Int * info)
+{
+    Pieusb_Scanner *scanner = handle;
+    SANE_Status status;
+    SANE_Word cap;
+    SANE_String_Const name;
+
+    DBG(DBG_info_sane,"sane_control_option()\n");
+    if (info) {
+        *info = 0;
+    }
+
+    /* Don't set or get options while the scanner is busy */
+    if (scanner->scanning) {
+        DBG(DBG_error,"Device busy scanning, no option returned\n");
+        return SANE_STATUS_DEVICE_BUSY;
+    }
+
+    /* Check if option index is between bounds */
+    if ((unsigned) option >= NUM_OPTIONS) {
+        DBG(DBG_error,"Index too large, no option returned\n");
+        return SANE_STATUS_INVAL;
+    }
+
+    /* Check if option is switched on */
+    cap = scanner->opt[option].cap;
+    if (!SANE_OPTION_IS_ACTIVE (cap))
+    {
+        DBG(DBG_error,"Option inactive (%s)\n", scanner->opt[option].name);
+        return SANE_STATUS_INVAL;
+    }
+
+    /* Get name of option */
+    name = scanner->opt[option].name;
+    if (!name)
+    {
+      name = "(no name)";
+    }
+
+    /* */
+    switch (action) {
+        case SANE_ACTION_GET_VALUE:
+
+            DBG (DBG_info_sane, "get %s [#%d]\n", name, option);
+
+            switch (option) {
+
+                /* word options: */
+                case OPT_NUM_OPTS:
+                case OPT_BIT_DEPTH:
+                case OPT_RESOLUTION:
+                case OPT_TL_X:
+                case OPT_TL_Y:
+                case OPT_BR_X:
+                case OPT_BR_Y:
+                case OPT_THRESHOLD:
+                case OPT_SHARPEN:
+                case OPT_SHADING_ANALYSIS:
+                case OPT_FAST_INFRARED:
+	        case OPT_ADVANCE_SLIDE:
+                case OPT_CORRECT_SHADING:
+                case OPT_CORRECT_INFRARED:
+                case OPT_CLEAN_IMAGE:
+                case OPT_SMOOTH_IMAGE:
+                case OPT_TRANSFORM_TO_SRGB:
+                case OPT_INVERT_IMAGE:
+                case OPT_PREVIEW:
+                case OPT_SAVE_SHADINGDATA:
+                case OPT_SAVE_CCDMASK:
+	        case OPT_LIGHT:
+	        case OPT_DOUBLE_TIMES:
+                case OPT_SET_EXPOSURE_R:
+                case OPT_SET_EXPOSURE_G:
+                case OPT_SET_EXPOSURE_B:
+                case OPT_SET_EXPOSURE_I:
+                case OPT_SET_GAIN_R:
+                case OPT_SET_GAIN_G:
+                case OPT_SET_GAIN_B:
+                case OPT_SET_GAIN_I:
+                case OPT_SET_OFFSET_R:
+                case OPT_SET_OFFSET_G:
+                case OPT_SET_OFFSET_B:
+                case OPT_SET_OFFSET_I:
+                    *(SANE_Word *) val = scanner->val[option].w;
+                    DBG (DBG_info_sane, "get %s [#%d] val=%d\n", name, option,scanner->val[option].w);
+                    return SANE_STATUS_GOOD;
+
+                /* word-array options: => for exposure gain offset? */
+                case OPT_CROP_IMAGE:
+                    memcpy (val, scanner->val[option].wa, scanner->opt[option].size);
+                    return SANE_STATUS_GOOD;
+
+                /* string options */
+                case OPT_MODE:
+                case OPT_CALIBRATION_MODE:
+                case OPT_GAIN_ADJUST:
+                case OPT_HALFTONE_PATTERN:
+                    strcpy (val, scanner->val[option].s);
+                    DBG (DBG_info_sane, "get %s [#%d] val=%s\n", name, option,scanner->val[option].s);
+                    return SANE_STATUS_GOOD;
+            }
+            break;
+
+        case SANE_ACTION_SET_VALUE:
+
+            switch (scanner->opt[option].type) {
+                case SANE_TYPE_INT:
+                    DBG (DBG_info_sane, "set %s [#%d] to %d, size=%d\n", name, option, *(SANE_Word *) val, scanner->opt[option].size);
+                    break;
+                case SANE_TYPE_FIXED:
+                    DBG (DBG_info_sane, "set %s [#%d] to %f\n", name, option, SANE_UNFIX (*(SANE_Word *) val));
+                    break;
+                case SANE_TYPE_STRING:
+                    DBG (DBG_info_sane, "set %s [#%d] to %s\n", name, option, (char *) val);
+                    break;
+                case SANE_TYPE_BOOL:
+                    DBG (DBG_info_sane, "set %s [#%d] to %d\n", name, option, *(SANE_Word *) val);
+                    break;
+                default:
+                    DBG (DBG_info_sane, "set %s [#%d]\n", name, option);
+            }
+            /* Check if option can be set */
+            if (!SANE_OPTION_IS_SETTABLE (cap)) {
+              return SANE_STATUS_INVAL;
+            }
+            /* Check if new value within bounds */
+            status = sanei_constrain_value (scanner->opt + option, val, info);
+            if (status != SANE_STATUS_GOOD) {
+              return status;
+            }
+            /* Set option and handle info return */
+            switch (option)
+            {
+                /* (mostly) side-effect-free word options: */
+                case OPT_BIT_DEPTH:
+                case OPT_RESOLUTION:
+                case OPT_TL_X:
+                case OPT_TL_Y:
+                case OPT_BR_X:
+                case OPT_BR_Y:
+                case OPT_SHARPEN:
+                case OPT_SHADING_ANALYSIS:
+                case OPT_FAST_INFRARED:
+                    if (info) {
+                        *info |= SANE_INFO_RELOAD_PARAMS;
+                    }
+                  /* fall through */
+                case OPT_NUM_OPTS:
+                case OPT_PREVIEW:
+	        case OPT_ADVANCE_SLIDE:
+                case OPT_CORRECT_SHADING:
+                case OPT_CORRECT_INFRARED:
+                case OPT_CLEAN_IMAGE:
+                case OPT_SMOOTH_IMAGE:
+                case OPT_TRANSFORM_TO_SRGB:
+                case OPT_INVERT_IMAGE:
+                case OPT_SAVE_SHADINGDATA:
+                case OPT_SAVE_CCDMASK:
+                case OPT_THRESHOLD:
+	        case OPT_LIGHT:
+	        case OPT_DOUBLE_TIMES:
+                case OPT_SET_GAIN_R:
+                case OPT_SET_GAIN_G:
+                case OPT_SET_GAIN_B:
+                case OPT_SET_GAIN_I:
+                case OPT_SET_OFFSET_R:
+                case OPT_SET_OFFSET_G:
+                case OPT_SET_OFFSET_B:
+                case OPT_SET_OFFSET_I:
+                case OPT_SET_EXPOSURE_R:
+                case OPT_SET_EXPOSURE_G:
+                case OPT_SET_EXPOSURE_B:
+                case OPT_SET_EXPOSURE_I:
+                    scanner->val[option].w = *(SANE_Word *) val;
+                    break;
+
+                /* side-effect-free word-array options: */
+                case OPT_CROP_IMAGE:
+                    memcpy (scanner->val[option].wa, val, scanner->opt[option].size);
+                    break;
+
+                /* options with side-effects: */
+                case OPT_MODE:
+                {
+                    /* Free current setting */
+                    if (scanner->val[option].s) {
+                        free (scanner->val[option].s);
+                    }
+                    /* New setting */
+                    scanner->val[option].s = (SANE_Char *) strdup (val);
+                    /* Info */
+                    if (info) {
+                        *info |= SANE_INFO_RELOAD_OPTIONS | SANE_INFO_RELOAD_PARAMS;
+                    }
+                    break;
+                }
+
+                case OPT_CALIBRATION_MODE:
+                case OPT_GAIN_ADJUST:
+                case OPT_HALFTONE_PATTERN:
+                {
+                     /* Free current setting */
+                    if (scanner->val[option].s) {
+                        free (scanner->val[option].s);
+                    }
+                    /* New setting */
+                    scanner->val[option].s = (SANE_Char *) strdup (val);
+                    break;
+                }
+
+            }
+
+            /* Check the whole set */
+            if (sanei_pieusb_analyse_options(scanner)) {
+                return SANE_STATUS_GOOD;
+            } else {
+                return SANE_STATUS_INVAL;
+            }
+
+            break;
+        default:
+            return SANE_STATUS_INVAL;
+            break;
+    }
+    return SANE_STATUS_INVAL;
+}
+
+/**
+ * Obtain the current scan parameters. The returned parameters are guaranteed
+ * to be accurate between the time a scan has been started (sane start() has
+ * been called) and the completion of that request. Outside of that window, the
+ * returned values are best-effort estimates of what the parameters will be when
+ * sane start() gets invoked. - says the SANE standard.
+ *
+ * @param handle Scanner handle
+ * @param params Scan parameters
+ * @return SANE_STATUS_GOOD
+ */
+SANE_Status
+sane_get_parameters (SANE_Handle handle, SANE_Parameters * params)
+{
+    Pieusb_Scanner *scanner = handle;
+    const char *mode;
+    double resolution, width, height;
+    SANE_Int colors;
+
+    DBG (DBG_info_sane, "sane_get_parameters\n");
+
+    if (params) {
+
+        if (scanner->scanning) {
+            /* sane_start() initialized a SANE_Parameters struct in the scanner */
+            DBG (DBG_info_sane, "sane_get_parameters from scanner values\n");
+            params->bytes_per_line = scanner->scan_parameters.bytes_per_line;
+            params->depth = scanner->scan_parameters.depth;
+            params->format = scanner->scan_parameters.format;
+            params->last_frame = scanner->scan_parameters.last_frame;
+            params->lines = scanner->scan_parameters.lines;
+            params->pixels_per_line = scanner->scan_parameters.pixels_per_line;
+        } else {
+            /* Calculate appropriate values from option settings */
+            DBG (DBG_info_sane, "sane_get_parameters from option values\n");
+            if (scanner->val[OPT_PREVIEW].b) {
+                resolution = scanner->device->fast_preview_resolution;
+            } else {
+                resolution = SANE_UNFIX(scanner->val[OPT_RESOLUTION].w);
+            }
+            DBG (DBG_info_sane, "  resolution %f\n", resolution);
+            width = SANE_UNFIX(scanner->val[OPT_BR_X].w)-SANE_UNFIX(scanner->val[OPT_TL_X].w);
+            height = SANE_UNFIX(scanner->val[OPT_BR_Y].w)-SANE_UNFIX(scanner->val[OPT_TL_Y].w);
+            DBG (DBG_info_sane, "  width x height: %f x %f\n", width, height);
+            params->lines = height / MM_PER_INCH * resolution;
+            params->pixels_per_line = width / MM_PER_INCH * resolution;
+            mode = scanner->val[OPT_MODE].s;
+            if (strcmp(mode, SANE_VALUE_SCAN_MODE_LINEART) == 0) {
+                params->format = SANE_FRAME_GRAY;
+                params->depth = 1;
+                colors = 1;
+            } else if(strcmp(mode, SANE_VALUE_SCAN_MODE_HALFTONE) == 0) {
+                params->format = SANE_FRAME_GRAY;
+                params->depth = 1;
+                colors = 1;
+            } else if(strcmp(mode, SANE_VALUE_SCAN_MODE_GRAY) == 0) {
+                params->format = SANE_FRAME_GRAY;
+                params->depth = scanner->val[OPT_BIT_DEPTH].w;
+                colors = 1;
+            } else if(strcmp(mode, SANE_VALUE_SCAN_MODE_RGBI) == 0) {
+                params->format = SANE_FRAME_RGB; /* was: SANE_FRAME_RGBI */
+                params->depth = scanner->val[OPT_BIT_DEPTH].w;
+                colors = 4;
+            } else { /* SANE_VALUE_SCAN_MODE_COLOR */
+                params->format = SANE_FRAME_RGB;
+                params->depth = scanner->val[OPT_BIT_DEPTH].w;
+                colors = 3;
+            }
+            DBG (DBG_info_sane, "  colors: %d\n", colors);
+            if (params->depth == 1) {
+                params->bytes_per_line = colors * (params->pixels_per_line + 7)/8;
+            } else if (params->depth <= 8) {
+                params->bytes_per_line = colors * params->pixels_per_line;
+            } else if (params->depth <= 16) {
+                params->bytes_per_line = 2 * colors * params->pixels_per_line;
+            }
+            params->last_frame = SANE_TRUE;
+        }
+
+        DBG(DBG_info_sane,"sane_get_parameters(): SANE parameters\n");
+        DBG(DBG_info_sane," format = %d\n",params->format);
+        DBG(DBG_info_sane," last_frame = %d\n",params->last_frame);
+        DBG(DBG_info_sane," bytes_per_line = %d\n",params->bytes_per_line);
+        DBG(DBG_info_sane," pixels_per_line = %d\n",params->pixels_per_line);
+        DBG(DBG_info_sane," lines = %d\n",params->lines);
+        DBG(DBG_info_sane," depth = %d\n",params->depth);
+
+    } else {
+
+        DBG(DBG_info_sane," no params argument, no values returned\n");
+
+    }
+
+    return SANE_STATUS_GOOD;
+}
+
+/**
+ * Initiates aquisition of an image from the scanner.
+ * SCAN Phase 1: initialization and calibration
+ * (SCAN Phase 2: line-by-line scan & read is not implemented)
+ * SCAN Phase 3: get CCD-mask
+ * SCAN phase 4: scan slide and save data in scanner buffer
+
+ * @param handle Scanner handle
+ * @return
+ */
+SANE_Status
+sane_start (SANE_Handle handle)
+{
+    struct Pieusb_Scanner *scanner = handle;
+    struct Pieusb_Command_Status status;
+    SANE_Byte colors;
+    const char *mode;
+    SANE_Bool shading_correction_relevant;
+    SANE_Bool infrared_post_processing_relevant;
+    SANE_Status st;
+    SANE_Int bytes_per_line;
+
+    SANE_Int shading_width;
+    SANE_Int shading_idx;
+
+    struct Pieusb_Exposure_Time exptime = {
+      0x93, /* code 0x93 */
+      3 * 2 * sizeof(SANE_Int), /* number of bytes in rest of structure */
+      { { 0x02, 100 }, { 0x04, 100 }, { 0x08, 100 } }
+    };
+
+    struct Pieusb_Highlight_Shadow shadow = {
+      0x94, /* code 0x94 */
+      3 * 2 * sizeof(SANE_Int), /* number of bytes in rest of structure */
+      { { 0x02, 100 }, { 0x04, 100 }, { 0x08, 100 } }
+    };
+
+    DBG (DBG_info_sane, "sane_start()\n");
+
+    /* ----------------------------------------------------------------------
+     *
+     * Exit if currently scanning
+     *
+     * ---------------------------------------------------------------------- */
+    if (scanner->scanning) {
+        DBG (DBG_error, "sane_start(): scanner is already scanning, exiting\n");
+        return SANE_STATUS_DEVICE_BUSY;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Exit with pause if not warmed up
+     *
+     * ---------------------------------------------------------------------- */
+
+    sanei_pieusb_cmd_read_state (scanner->device_number, &(scanner->state), &status);
+    if (status.pieusb_status != PIEUSB_STATUS_GOOD) {
+        if (status.pieusb_status == PIEUSB_STATUS_DEVICE_BUSY)
+	  return SANE_STATUS_DEVICE_BUSY; /* was: SANE_STATUS_WARMING_UP */
+        DBG (DBG_error, "sane_start(): warmed up check returns status: %s\n",  sane_strstatus (sanei_pieusb_convert_status(status.pieusb_status)));
+        return SANE_STATUS_IO_ERROR;
+    }
+    if (scanner->state.warmingUp) {
+        DBG (DBG_error, "sane_start(): warming up, exiting\n");
+        /* Seen SANE_STATUS_WARMING_UP in scanimage => enabled */
+        sleep (10); /* scanimage does not pause, so do it here */
+        return SANE_STATUS_DEVICE_BUSY; /* was: SANE_STATUS_WARMING_UP */
+    }
+
+    /* ----------------------------------------------------------------------
+     * set exposure time
+     * ---------------------------------------------------------------------- */
+
+    sanei_pieusb_cmd_set_exposure_time (scanner->device_number, &exptime, &status);
+    if (status.pieusb_status != PIEUSB_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start(): sanei_pieusb_cmd_set_exposure_time failed: %d\n", status.pieusb_status);
+      return SANE_STATUS_IO_ERROR;
+    }
+
+    /* ----------------------------------------------------------------------
+     * set highlight shadow
+     * ---------------------------------------------------------------------- */
+
+    sanei_pieusb_cmd_set_highlight_shadow (scanner->device_number, &shadow, &status);
+    if (status.pieusb_status != PIEUSB_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start(): sanei_pieusb_cmd_set_highlight_shadow failed: %d\n", status.pieusb_status);
+      return SANE_STATUS_IO_ERROR;
+    }
+
+    /* ----------------------------------------------------------------------
+     * get calibration info
+     * ---------------------------------------------------------------------- */
+
+    sanei_pieusb_cmd_get_shading_parms (scanner->device_number, scanner->device->shading_parameters, &status);
+    if (status.pieusb_status != PIEUSB_STATUS_GOOD) {
+      DBG (DBG_error, "sane_scan: sanei_pieusb_cmd_get_shading_parms failed: %d\n", status.pieusb_status);
+      return SANE_STATUS_INVAL;
+    }
+    shading_width = scanner->device->shading_parameters[0].pixelsPerLine;
+    DBG (DBG_info, "shading_width %d\n", shading_width);
+    for (shading_idx = 0; shading_idx < SHADING_PARAMETERS_INFO_COUNT; shading_idx++) {
+      scanner->shading_ref[shading_idx] =
+        realloc(scanner->shading_ref[shading_idx], 2 * shading_width * sizeof(SANE_Int));
+      if (scanner->shading_ref[shading_idx] == NULL) {
+        return SANE_STATUS_NO_MEM;
+      }
+    }
+    scanner->ccd_mask = realloc (scanner->ccd_mask, shading_width);
+    scanner->ccd_mask_size = shading_width;
+    if (scanner->ccd_mask == NULL) {
+      return SANE_STATUS_NO_MEM;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Standard run does;
+     * - set exposure time 0x0A/0x13
+     * - set highlight shadow 0x0A/0x14
+     * - read shading parameters 0x0A/0x95/0x08
+     * - set scan frame 0x0A/0x12
+     *   "12 00 0a00 80 00 0300 0000 b829 e31a"
+     *    => 0:12 1:0 2:10 4:80 5:0 6:3 8:0 10:10680 12:6883
+     * - read gain offset 0xD7
+     * - set gain offset 0xDC
+     * - set mode 0x15
+     *   "00 0f   2c01 80   04  04  00 01    0a     00 00 00  80  10 00"
+     *       size res  pass dpt frm    ord   bitmap       ptn thr
+     *       15   300  RGB  8   inx    intel 1=sharpen    0   128
+     *                                       3=skipshad
+     *
+     * ---------------------------------------------------------------------- */
+
+    /* ----------------------------------------------------------------------
+     *
+     * Show and check options
+     *
+     * ---------------------------------------------------------------------- */
+    sanei_pieusb_print_options (scanner);
+    if (!sanei_pieusb_analyse_options (scanner)) {
+        return SANE_STATUS_IO_ERROR;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Set scan frame
+     *
+     * ---------------------------------------------------------------------- */
+    if (sanei_pieusb_set_frame_from_options (scanner) != SANE_STATUS_GOOD) {
+        return SANE_STATUS_IO_ERROR;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Function 17
+     *
+     * ---------------------------------------------------------------------- */
+
+    sanei_pieusb_cmd_17 (scanner->device_number, 1, &status);
+    if (status.pieusb_status != PIEUSB_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start(): sanei_pieusb_cmd_17 failed: %d\n", status.pieusb_status);
+      return SANE_STATUS_IO_ERROR;
+    }
+    st = sanei_pieusb_wait_ready (scanner, 0);
+    if (st != SANE_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start(): scanner not ready after sanei_pieusb_cmd_17: %d\n", st);
+      return st;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Get & set initial gains and offsets
+     *
+     * There does not seem to be much reason to set exposure/gain/offset
+     * now, but it does make a large difference in speed, because it
+     * creates a small BADF-table. This is probably because without SET GAIN
+     * OFFSET, extraEntries has a random value (it is not initialised).
+     *
+     * TODO: test if this may be done just once, in sane_open().
+     *
+     * ---------------------------------------------------------------------- */
+
+    if (sanei_pieusb_set_gain_offset (scanner, scanner->val[OPT_CALIBRATION_MODE].s) != SANE_STATUS_GOOD) {
+        return SANE_STATUS_IO_ERROR;
+    }
+
+    st = sanei_pieusb_wait_ready (scanner, 0);
+    if (st != SANE_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start: scanner not ready %d\n", st);
+      return st;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Set mode
+     *
+     * ---------------------------------------------------------------------- */
+    if (sanei_pieusb_set_mode_from_options (scanner) != SANE_STATUS_GOOD) {
+        return SANE_STATUS_IO_ERROR;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Lamp on
+     *
+     * ---------------------------------------------------------------------- */
+    sanei_pieusb_cmd_slide (scanner->device_number, SLIDE_LAMP_ON, &status);
+    if (status.pieusb_status != PIEUSB_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start(): sanei_pieusb_cmd_slide failed: %d\n", status.pieusb_status);
+      return SANE_STATUS_IO_ERROR;
+    }
+    st = sanei_pieusb_wait_ready (scanner, 0);
+    if (st != SANE_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start: scanner not ready %d\n", st);
+      return st;
+    }
+
+    /* Enter SCAN phase 1 */
+    DBG (DBG_info_sane, "sane_start(): scan phase 1\n");
+
+    /* ----------------------------------------------------------------------
+     *
+     * Start scan & wait until device ready
+     *
+     * ---------------------------------------------------------------------- */
+    scanner->scanning = SANE_TRUE;
+    scanner->cancel_request = SANE_FALSE;
+    for (;;) {
+      sanei_pieusb_cmd_start_scan (scanner->device_number, &status);
+      if (status.pieusb_status != PIEUSB_STATUS_WARMING_UP)
+	break;
+      sleep(5);
+    }
+    sanei_pieusb_wait_ready (scanner, 0);
+    if ((status.pieusb_status == PIEUSB_STATUS_MUST_CALIBRATE)
+        || (scanner->val[OPT_SHADING_ANALYSIS].b != 0)) {
+
+        /* Overriding skip calibration */
+        DBG (DBG_info_sane, "sane_start(): process shading data\n");
+
+        /* ------------------------------------------------------------------
+         *
+         * Get and set gain and offset
+         * Get settings from scanner, from preview data, from options,
+         * or use defaults.
+         *
+         * ------------------------------------------------------------------ */
+        if (sanei_pieusb_set_gain_offset (scanner, scanner->val[OPT_CALIBRATION_MODE].s) != SANE_STATUS_GOOD) {
+            sanei_pieusb_cmd_stop_scan (scanner->device_number, &status);
+            scanner->scanning = SANE_FALSE;
+            return SANE_STATUS_IO_ERROR;
+        }
+        /* ------------------------------------------------------------------
+         *
+         * Obtain shading data
+         * Get parameters from scanner->device->shading_parameters[0] although
+         * it's 45 lines, scanner->ccd_mask_size pixels, 16 bit depth in all cases.
+         *
+         * ------------------------------------------------------------------ */
+        if (sanei_pieusb_get_shading_data (scanner) != SANE_STATUS_GOOD) {
+            sanei_pieusb_cmd_stop_scan (scanner->device_number, &status);
+            scanner->scanning = SANE_FALSE;
+            return SANE_STATUS_IO_ERROR;
+        }
+    }
+
+    /* Enter SCAN phase 2 */
+    DBG (DBG_info_sane, "sane_start(): scan phase 2\n");
+
+    /* SCAN phase 2 (line-by-line scan) not implemented */
+
+    st = sanei_pieusb_wait_ready (scanner, 0);
+    if (st != SANE_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start: scanner not ready %d\n", st);
+      return st;
+    }
+
+    /* Enter SCAN phase 3 */
+
+    DBG (DBG_info_sane, "sane_start(): scan phase 3\n");
+
+    /* Handle cancel request */
+    if (scanner->cancel_request) {
+        return sanei_pieusb_on_cancel (scanner);
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Get CCD mask
+     *
+     * ---------------------------------------------------------------------- */
+
+    if (sanei_pieusb_get_ccd_mask (scanner) != SANE_STATUS_GOOD) {
+        sanei_pieusb_cmd_stop_scan (scanner->device_number, &status);
+        scanner->scanning = SANE_FALSE;
+        return SANE_STATUS_IO_ERROR;
+    }
+
+    /* Enter SCAN phase 4 */
+
+    /* ----------------------------------------------------------------------
+     *
+     * Read scan parameters & wait until ready for reading
+     *
+     * ---------------------------------------------------------------------- */
+    if (sanei_pieusb_get_parameters (scanner, &bytes_per_line) != SANE_STATUS_GOOD) {
+        sanei_pieusb_cmd_stop_scan (scanner->device_number, &status);
+        scanner->scanning = SANE_FALSE;
+        return SANE_STATUS_IO_ERROR;
+    }
+
+    st = sanei_pieusb_wait_ready (scanner, 0);
+    if (st != SANE_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start: scanner not ready %d\n", st);
+      return st;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Prepare read buffer
+     * Currently this buffer is always a memory mapped buffer
+     * Might be faster to use RAM buffers for small images (such as preview)
+     *
+     * ---------------------------------------------------------------------- */
+    colors = 0x00;
+    switch (scanner->mode.passes) {
+        case SCAN_FILTER_RED: colors = 0x01; break;
+        case SCAN_FILTER_GREEN: colors = 0x02; break;
+        case SCAN_FILTER_BLUE: colors = 0x04; break;
+        case SCAN_FILTER_INFRARED: colors = 0x08; break;
+        case SCAN_ONE_PASS_COLOR: colors = 0x07; break;
+        case SCAN_ONE_PASS_RGBI: colors = 0x0F; break;
+    }
+    if (scanner->buffer.data) sanei_pieusb_buffer_delete(&scanner->buffer); /* free resources from previous invocation */
+    st = sanei_pieusb_buffer_create (&(scanner->buffer), scanner->scan_parameters.pixels_per_line,
+			       scanner->scan_parameters.lines, colors,
+			       scanner->scan_parameters.depth);
+    if (st != SANE_STATUS_GOOD) {
+        scanner->scanning = SANE_FALSE;
+        return st;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Read all image data into the buffer
+     *
+     * ---------------------------------------------------------------------- */
+    if (sanei_pieusb_get_scan_data (scanner, bytes_per_line) != SANE_STATUS_GOOD) {
+        scanner->scanning = SANE_FALSE;
+        return SANE_STATUS_IO_ERROR;
+    }
+    sleep(2);
+    st = sanei_pieusb_wait_ready (scanner, 0);
+    if (st != SANE_STATUS_GOOD) {
+      DBG (DBG_error, "sane_start(): scanner not ready after sanei_pieusb_get_scan_data: %d\n", st);
+      scanner->scanning = SANE_FALSE;
+      return st;
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Advance to next slide (except for preview)
+     *
+     * ---------------------------------------------------------------------- */
+    if (scanner->val[OPT_ADVANCE_SLIDE].b && !scanner->val[OPT_PREVIEW].b) {
+      sanei_pieusb_cmd_slide (scanner->device_number, SLIDE_NEXT, &status);
+      if (status.pieusb_status != PIEUSB_STATUS_GOOD) {
+	DBG (DBG_error, "sane_start(): sanei_pieusb_cmd_slide failed: %d\n", status.pieusb_status);
+
+      }
+    }
+
+    /* ----------------------------------------------------------------------
+     *
+     * Post processing:
+     * 1. Correct for shading
+     * 2. Remove R-component from IR data
+     * 3. Remove dust
+     *
+     * ---------------------------------------------------------------------- */
+
+    mode = scanner->val[OPT_MODE].s;
+    if (strcmp(mode, SANE_VALUE_SCAN_MODE_LINEART) == 0) {
+        shading_correction_relevant = SANE_FALSE; /* Shading correction irrelavant at bit depth 1 */
+        infrared_post_processing_relevant = SANE_FALSE; /* No infrared, no postprocessing */
+    } else if (strcmp(mode, SANE_VALUE_SCAN_MODE_HALFTONE) == 0) {
+        shading_correction_relevant = SANE_FALSE; /* Shading correction irrelavant at bit depth 1 */
+        infrared_post_processing_relevant = SANE_FALSE; /* No infrared, no postprocessing */
+    } else if (strcmp(mode, SANE_VALUE_SCAN_MODE_GRAY) == 0) {
+        shading_correction_relevant = SANE_TRUE;
+        infrared_post_processing_relevant = SANE_FALSE; /* No infrared, no postprocessing */
+    } else if (scanner->val[OPT_PREVIEW].b) {
+        /* Catch preview here, otherwise next ifs get complicated */
+        shading_correction_relevant = SANE_TRUE;
+        infrared_post_processing_relevant = SANE_FALSE;
+    } else if (strcmp(mode, SANE_VALUE_SCAN_MODE_RGBI) == 0) {
+        shading_correction_relevant = SANE_TRUE;
+        infrared_post_processing_relevant = SANE_TRUE;
+    } else if (strcmp(mode, SANE_VALUE_SCAN_MODE_COLOR) == 0 && scanner->val[OPT_CLEAN_IMAGE].b) {
+        shading_correction_relevant = SANE_TRUE;
+        infrared_post_processing_relevant = SANE_TRUE;
+    } else { /* SANE_VALUE_SCAN_MODE_COLOR */
+        shading_correction_relevant = SANE_TRUE;
+        infrared_post_processing_relevant = SANE_TRUE;
+    }
+    if (scanner->val[OPT_CORRECT_SHADING].b && shading_correction_relevant) {
+        if (scanner->shading_data_present) {
+            sanei_pieusb_correct_shading (scanner, &scanner->buffer);
+        } else {
+            DBG(DBG_warning, "sane_start(): unable to correct for shading, no shading data available\n");
+        }
+    }
+    if ((scanner->val[OPT_CORRECT_INFRARED].b || scanner->val[OPT_CLEAN_IMAGE].b) && !scanner->val[OPT_PREVIEW].b && infrared_post_processing_relevant) {
+        /* Create array of pointers to color planes R, G, B, I */
+        SANE_Uint *planes[PLANES];
+        SANE_Int N;
+        N = scanner->buffer.width * scanner->buffer.height;
+        planes[0] = scanner->buffer.data;
+        planes[1] = scanner->buffer.data + N;
+        planes[2] = scanner->buffer.data + 2 * N;
+        planes[3] = scanner->buffer.data + 3 * N;
+        sanei_ir_init ();
+        sanei_pieusb_post (scanner, planes, scanner->buffer.colors);
+    }
+
+    /* Save preview data. Preview data only used once to set gain and offset. */
+    if (scanner->val[OPT_PREVIEW].b) {
+        sanei_pieusb_analyze_preview(scanner);
+    } else {
+        scanner->preview_done = SANE_FALSE;
+    }
+
+    /* Modify buffer in case the buffer has infrared, but no infrared should be returned */
+    if (scanner->buffer.colors == PLANES && (strcmp(mode,SANE_VALUE_SCAN_MODE_COLOR) == 0 && scanner->val[OPT_CLEAN_IMAGE].b)) {
+        DBG(DBG_info_sane, "sane_start(): modifying buffer to ignore I\n");
+        /* Base buffer parameters */
+        scanner->buffer.colors = 3;
+        /* Derived quantities */
+        scanner->buffer.image_size_bytes = scanner->buffer.colors * scanner->buffer.height * scanner->buffer.line_size_bytes;
+        scanner->buffer.color_index_infrared = -1;
+        scanner->buffer.bytes_unread = scanner->buffer.bytes_unread * 3 / 4;
+        scanner->buffer.bytes_written = scanner->buffer.bytes_written * 3 / 4;
+    }
+
+    return SANE_STATUS_GOOD;
+
+}
+
+/**
+ * Read image data from the scanner buffer.
+ *
+ * @param handle
+ * @param buf
+ * @param max_len
+ * @param len
+ * @return
+ */
+SANE_Status
+sane_read (SANE_Handle handle, SANE_Byte * buf, SANE_Int max_len, SANE_Int * len)
+{
+
+    struct Pieusb_Scanner *scanner = handle;
+    SANE_Int return_size;
+
+    DBG(DBG_info_sane, "sane_read(): requested %d bytes\n", max_len);
+
+    /* No reading if not scanning */
+    if (!scanner->scanning) {
+        *len = 0;
+        return SANE_STATUS_IO_ERROR; /* SANE standard does not allow a SANE_STATUS_INVAL return */
+    }
+
+    /* Handle cancel request */
+    if (scanner->cancel_request) {
+        return sanei_pieusb_on_cancel(scanner);
+    }
+#if 0
+    /* Return image data, just read from scanner buffer */
+    DBG(DBG_info_sane, "sane_read():\n");
+    DBG(DBG_info_sane, "  image size %d\n", scanner->buffer.image_size_bytes);
+    DBG(DBG_info_sane, "  unread     %d\n", scanner->buffer.bytes_unread);
+    DBG(DBG_info_sane, "  read       %d\n", scanner->buffer.bytes_read);
+    DBG(DBG_info_sane, "  max_len    %d\n", max_len);
+#endif
+    if (scanner->buffer.bytes_read > scanner->buffer.image_size_bytes) {
+        /* Test if not reading past buffer boundaries */
+        DBG(DBG_error, "sane_read(): reading past buffer boundaries (contains %d, read %d)\n", scanner->buffer.image_size_bytes, scanner->buffer.bytes_read);
+        *len = 0;
+        sanei_pieusb_on_cancel(scanner);
+        return SANE_STATUS_EOF;
+    } else if (scanner->buffer.bytes_read == scanner->buffer.image_size_bytes) {
+        /* Return EOF since all data of this frame has already been read. */
+        *len = 0;
+        scanner->scanning = SANE_FALSE;
+        return SANE_STATUS_EOF;
+    } else if (scanner->buffer.bytes_unread >= max_len) {
+        /* Already enough data to return, do not read */
+        DBG(DBG_info_sane, "sane_read(): buffer suffices (contains %d, requested %d)\n", scanner->buffer.bytes_unread, max_len);
+        return_size = max_len;
+    } else if (scanner->buffer.bytes_read + scanner->buffer.bytes_unread == scanner->buffer.image_size_bytes) {
+        /* All the remaining data is in the buffer, do not read */
+        DBG(DBG_info_sane, "sane_read(): buffer suffices (contains %d, requested %d, last batch though)\n", scanner->buffer.bytes_unread, max_len);
+        return_size = scanner->buffer.bytes_unread;
+    } else {
+        /* Should not happen in this implementation - all data read by sane_start() */
+        DBG(DBG_error, "sane_read(): shouldn't be here...\n");
+        return SANE_STATUS_IO_ERROR;
+    }
+
+    /* Check */
+    if (return_size == 0 && scanner->buffer.bytes_read < scanner->buffer.image_size_bytes) {
+        DBG(DBG_error, "sane_read(): unable to service read request, %d bytes in frame, %d read\n", scanner->buffer.image_size_bytes, scanner->buffer.bytes_read);
+    }
+
+    /* Return the available data: Output return_size bytes from buffer */
+    sanei_pieusb_buffer_get(&scanner->buffer, buf, max_len, len);
+#if 0
+    DBG(DBG_info_sane, "sane_read(): currently read %.2f lines of %d\n",
+      (double)scanner->buffer.bytes_written/(scanner->buffer.line_size_bytes*scanner->buffer.colors),
+      scanner->buffer.height);
+    DBG(DBG_info_sane, "sane_read(): returning %d bytes (requested %d), returned %d of %d \n",
+      *len, max_len,scanner->buffer.bytes_read, scanner->buffer.image_size_bytes);
+#endif
+    return SANE_STATUS_GOOD;
+
+}
+
+/**
+ * Request cancellation of current scanning process.
+ *
+ * @param handle Scanner handle
+ */
+void
+sane_cancel (SANE_Handle handle)
+{
+    struct Pieusb_Scanner *scanner = handle;
+
+    DBG (DBG_info_sane, "sane_cancel\n");
+
+    if (scanner->scanning) {
+        scanner->cancel_request = 1;
+    }
+}
+
+/**
+ * Set the I/O mode of handle h. The I/O mode can be either blocking or
+ * non-blocking, but for USB devices, only blocking mode is supported.
+ *
+ * @param handle Scanner handle
+ * @param non_blocking
+ * @return SANE_STATUS_UNSUPPORTED;
+ */
+SANE_Status
+sane_set_io_mode (SANE_Handle handle, SANE_Bool non_blocking)
+{
+    /* Pieusb_Scanner *scanner = handle; */
+
+    DBG (DBG_info_sane, "sane_set_io_mode: handle = %p, non_blocking = %s\n", handle, non_blocking == SANE_TRUE ? "true" : "false");
+
+    if (non_blocking) {
+	return SANE_STATUS_UNSUPPORTED;
+    }
+
+    return SANE_STATUS_GOOD;
+}
+
+/**
+ * Obtain a file-descriptor for the scanner that is readable if image data is
+ * available. The select file-descriptor is returned in *fd.
+ * The function has not been implemented since USB-device only operate in
+ * blocking mode.
+ *
+ * @param handle Scanner handle
+ * @param fd File descriptor with imae data
+ * @return SANE_STATUS_INVAL
+ */
+SANE_Status
+sane_get_select_fd (SANE_Handle handle, SANE_Int * fd)
+{
+    DBG(DBG_info_sane,"sane_get_select_fd(): not supported (only for non-blocking IO)\n");
+    handle = handle;
+    fd = fd;
+    return SANE_STATUS_UNSUPPORTED;
+}