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authorJörg Frings-Fürst <debian@jff-webhosting.net>2020-02-02 17:13:01 +0100
committerJörg Frings-Fürst <debian@jff-webhosting.net>2020-02-02 17:13:01 +0100
commitffa8801644a7d53cc1c785e3450f794c07a14eb0 (patch)
tree8d72a18a9a08b9151d12badcb1c78ce06a059f62 /backend/genesys/conv.cpp
parent1687222e1b9e74c89cafbb5910e72d8ec7bfd40f (diff)
New upstream version 1.0.29upstream/1.0.29
Diffstat (limited to 'backend/genesys/conv.cpp')
-rw-r--r--backend/genesys/conv.cpp238
1 files changed, 238 insertions, 0 deletions
diff --git a/backend/genesys/conv.cpp b/backend/genesys/conv.cpp
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+/* sane - Scanner Access Now Easy.
+
+ Copyright (C) 2005, 2006 Pierre Willenbrock <pierre@pirsoft.dnsalias.org>
+ Copyright (C) 2010-2013 Stéphane Voltz <stef.dev@free.fr>
+
+ 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.
+*/
+
+#define DEBUG_DECLARE_ONLY
+
+#include "conv.h"
+#include "sane/sanei_magic.h"
+
+namespace genesys {
+
+/**
+ * uses the threshold/threshold_curve to control software binarization
+ * This code was taken from the epjistsu backend by m. allan noah
+ * @param dev device set up for the scan
+ * @param src pointer to raw data
+ * @param dst pointer where to store result
+ * @param width width of the processed line
+ * */
+void binarize_line(Genesys_Device* dev, std::uint8_t* src, std::uint8_t* dst, int width)
+{
+ DBG_HELPER(dbg);
+ int j, windowX, sum = 0;
+ int thresh;
+ int offset, addCol, dropCol;
+ unsigned char mask;
+
+ int x;
+ std::uint8_t min, max;
+
+ /* normalize line */
+ min = 255;
+ max = 0;
+ for (x = 0; x < width; x++)
+ {
+ if (src[x] > max)
+ {
+ max = src[x];
+ }
+ if (src[x] < min)
+ {
+ min = src[x];
+ }
+ }
+
+ /* safeguard against dark or white areas */
+ if(min>80)
+ min=0;
+ if(max<80)
+ max=255;
+ for (x = 0; x < width; x++)
+ {
+ src[x] = ((src[x] - min) * 255) / (max - min);
+ }
+
+ /* ~1mm works best, but the window needs to have odd # of pixels */
+ windowX = (6 * dev->settings.xres) / 150;
+ if (!(windowX % 2))
+ windowX++;
+
+ /* second, prefill the sliding sum */
+ for (j = 0; j < windowX; j++)
+ sum += src[j];
+
+ /* third, walk the input buffer, update the sliding sum, */
+ /* determine threshold, output bits */
+ for (j = 0; j < width; j++)
+ {
+ /* output image location */
+ offset = j % 8;
+ mask = 0x80 >> offset;
+ thresh = dev->settings.threshold;
+
+ /* move sum/update threshold only if there is a curve */
+ if (dev->settings.threshold_curve)
+ {
+ addCol = j + windowX / 2;
+ dropCol = addCol - windowX;
+
+ if (dropCol >= 0 && addCol < width)
+ {
+ sum -= src[dropCol];
+ sum += src[addCol];
+ }
+ thresh = dev->lineart_lut[sum / windowX];
+ }
+
+ /* use average to lookup threshold */
+ if (src[j] > thresh)
+ *dst &= ~mask; /* white */
+ else
+ *dst |= mask; /* black */
+
+ if (offset == 7)
+ dst++;
+ }
+}
+
+/**
+ * software lineart using data from a 8 bit gray scan. We assume true gray
+ * or monochrome scan as input.
+ */
+void genesys_gray_lineart(Genesys_Device* dev,
+ std::uint8_t* src_data, std::uint8_t* dst_data,
+ std::size_t pixels, std::size_t lines, std::uint8_t threshold)
+{
+ DBG_HELPER(dbg);
+ std::size_t y;
+
+ DBG(DBG_io2, "%s: converting %zu lines of %zu pixels\n", __func__, lines, pixels);
+ DBG(DBG_io2, "%s: threshold=%d\n", __func__, threshold);
+
+ for (y = 0; y < lines; y++)
+ {
+ binarize_line (dev, src_data + y * pixels, dst_data, pixels);
+ dst_data += pixels / 8;
+ }
+}
+
+/** Look in image for likely left/right/bottom paper edges, then crop image.
+ */
+void genesys_crop(Genesys_Scanner* s)
+{
+ DBG_HELPER(dbg);
+ Genesys_Device *dev = s->dev;
+ int top = 0;
+ int bottom = 0;
+ int left = 0;
+ int right = 0;
+
+ // first find edges if any
+ TIE(sanei_magic_findEdges(&s->params, dev->img_buffer.data(),
+ dev->settings.xres, dev->settings.yres,
+ &top, &bottom, &left, &right));
+
+ DBG (DBG_io, "%s: t:%d b:%d l:%d r:%d\n", __func__, top, bottom, left,
+ right);
+
+ // now crop the image
+ TIE(sanei_magic_crop (&(s->params), dev->img_buffer.data(), top, bottom, left, right));
+
+ /* update counters to new image size */
+ dev->total_bytes_to_read = s->params.bytes_per_line * s->params.lines;
+}
+
+/** Look in image for likely upper and left paper edges, then rotate
+ * image so that upper left corner of paper is upper left of image.
+ */
+void genesys_deskew(Genesys_Scanner *s, const Genesys_Sensor& sensor)
+{
+ DBG_HELPER(dbg);
+ Genesys_Device *dev = s->dev;
+
+ int x = 0, y = 0, bg;
+ double slope = 0;
+
+ bg=0;
+ if(s->params.format==SANE_FRAME_GRAY && s->params.depth == 1)
+ {
+ bg=0xff;
+ }
+ TIE(sanei_magic_findSkew(&s->params, dev->img_buffer.data(),
+ sensor.optical_res, sensor.optical_res,
+ &x, &y, &slope));
+
+ DBG(DBG_info, "%s: slope=%f => %f\n", __func__, slope, slope * 180 / M_PI);
+
+ // rotate image slope is in [-PI/2,PI/2]. Positive values rotate trigonometric direction wise
+ TIE(sanei_magic_rotate(&s->params, dev->img_buffer.data(),
+ x, y, slope, bg));
+}
+
+/** remove lone dots
+ */
+void genesys_despeck(Genesys_Scanner* s)
+{
+ DBG_HELPER(dbg);
+ TIE(sanei_magic_despeck(&s->params, s->dev->img_buffer.data(), s->despeck));
+}
+
+/** Look if image needs rotation and apply it
+ * */
+void genesys_derotate(Genesys_Scanner* s)
+{
+ DBG_HELPER(dbg);
+ int angle = 0;
+
+ TIE(sanei_magic_findTurn(&s->params, s->dev->img_buffer.data(),
+ s->resolution, s->resolution, &angle));
+
+ // apply rotation angle found
+ TIE(sanei_magic_turn(&s->params, s->dev->img_buffer.data(), angle));
+
+ // update counters to new image size
+ s->dev->total_bytes_to_read = s->params.bytes_per_line * s->params.lines;
+}
+
+} // namespace genesys