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Diffstat (limited to 'doc/sane-sharp.man')
| -rw-r--r-- | doc/sane-sharp.man | 162 |
1 files changed, 81 insertions, 81 deletions
diff --git a/doc/sane-sharp.man b/doc/sane-sharp.man index f089538..b4453ee 100644 --- a/doc/sane-sharp.man +++ b/doc/sane-sharp.man @@ -9,7 +9,7 @@ library implements a SANE (Scanner Access Now Easy) backend that provides access to Sharp SCSI scanners. This backend should be considered .B beta-quality -software! In the current state it is known to work with JX-610 and JX-250 +software! In the current state it is known to work with JX-610 and JX-250 scanners. It is prepared for usage with the JX-330 series scanners, but we are not able to test it with these devices. .PP @@ -63,18 +63,18 @@ for example. See sane\-scsi(5) for details. .SH SCAN OPTIONS .B Scan Mode -(parameter +(parameter .B \-\-mode -for scanimage). Possible settings: +for scanimage). Possible settings: .RS .B Lineart -(1 bit black & white scans), +(1 bit black & white scans), .br .B Gray (8 bit gray scale scans), .br .B Lineart Color -(bi-level color scans), +(bi-level color scans), .br .B Color (8 bit RGB scans). @@ -91,11 +91,11 @@ Possible settings: .B none .br .B Dither Bayer -.br +.br .B Dither Spiral .br .B Dither Dispersed -.br +.br .B Error Diffusion .RE The default value is @@ -114,12 +114,12 @@ feeder or a transparency adapter is installed. Possible settings: .B Transparency Adapter .RE If an ADF or a transparency adapter is installed, using it is the -default selection. +default selection. .B Custom Gamma -(parameter +(parameter .B \-\-custom\-gamma -for scanimage). This option determines whether a builtin or a custom +for scanimage). This option determines whether a builtin or a custom gamma-table is used. Possible settings: .RS .B yes @@ -130,11 +130,11 @@ enables a built gamma table .RE .B Gamma -(parameter +(parameter .B \-\-Gamma -for scanimage). This option is only available, if +for scanimage). This option is only available, if .B Custom Gamma -is set to +is set to .B no. Possible values: .RS @@ -142,32 +142,32 @@ Possible values: .br .B 2.2 .RE -The default value is 2.2. (The JX-250 and JX-350 have no built in gamma -correction; for these scanner, a gamma table is downloaded to the scanner +The default value is 2.2. (The JX-250 and JX-350 have no built in gamma +correction; for these scanner, a gamma table is downloaded to the scanner by the backend.) .B Gamma Table -(parameter +(parameter .B \-\-gamma\-table -for scanimage). Allowed values: 0..255; 256 numbers must be defined. -The default values are 0, 1, 2, .. 255 (i.e., gamma == 1). This table +for scanimage). Allowed values: 0..255; 256 numbers must be defined. +The default values are 0, 1, 2, .. 255 (i.e., gamma == 1). This table is only used for gray scale scans. .B Red Gamma Table -(parameter -.B \-\-red\-gamma\-table +(parameter +.B \-\-red\-gamma\-table for scanimage). Allowed values: 0..255; 256 numbers must be defined. The default values are 0, 1, 2, .. 255 (i.e., gamma == 1). .B Green Gamma Table -(parameter -.B \-\-green\-gamma\-table +(parameter +.B \-\-green\-gamma\-table for scanimage). Allowed values: 0..255; 256 numbers must be defined. The default values are 0, 1, 2, .. 255 (i.e., gamma == 1). .B Blue Gamma Table -(parameter -.B \-\-blue\-gamma\-table +(parameter +.B \-\-blue\-gamma\-table for scanimage). Allowed values: 0..255; 256 numbers must be defined. The default values are 0, 1, 2, .. 255 (i.e., gamma == 1). @@ -177,7 +177,7 @@ in pixel per inch (parameter for scanimage). Selects the resolution of the scanned image. Allowed values: .RS .B 30..600 -(JX-330, JX-350 and JX-610) resp. +(JX-330, JX-350 and JX-610) resp. .B 30..400 (JX-250) .RE @@ -203,19 +203,19 @@ in order to see the allowed parameter values for the scan window. The scan window parameters are: .RS -Top-left x position of scan area (parameter +Top-left x position of scan area (parameter .B \-l for scanimage); .br -Top-left y position of scan area (parameter +Top-left y position of scan area (parameter .B \-t for scanimage); .br -bottom right x position of scan area (parameter +bottom right x position of scan area (parameter .B \-x for scanimage); .br -bottom right y position of scan area (parameter +bottom right y position of scan area (parameter .B \-y for scanimage); .RE @@ -223,7 +223,7 @@ for scanimage); .B Edge emphasis (parameter .B \-\-Edge emphasis -for scanimage). This option is not available for the JX-250 and the JX-350. +for scanimage). This option is not available for the JX-250 and the JX-350. Possible settings: .RS .B None @@ -234,59 +234,59 @@ Possible settings: .br .B Blur .RE -The default value is +The default value is .B None. .B Threshold -(parameter +(parameter .B \-\-threshold for scanimage). Sets the threshold for black and white pixels in lineart mode. Possible values: .RS .B 1..255 .RE -The default value is +The default value is .B 128. This option is only available in scan mode lineart. .B Threshold Red -(parameter +(parameter .B \-\-threshold-red for scanimage). Sets the threshold for the red component of a pixel in in lineart color scan mode. Possible values: .RS .B 1..255 .RE -The default value is +The default value is .B 128. This option is only available in scan mode color lineart. .B Threshold Green -(parameter +(parameter .B \-\-threshold-green for scanimage). Sets the threshold for the green component of a pixel in in lineart color scan mode. Possible values: .RS .B 1..255 .RE -The default value is +The default value is .B 128. This option is only available in scan mode color lineart. .B Threshold Blue -(parameter +(parameter .B \-\-threshold-blue for scanimage). Sets the threshold for the blue component of a pixel in in lineart color scan mode. Possible values: .RS .B 1..255 .RE -The default value is +The default value is .B 128. This option is only available in scan mode color lineart. .B Light Color -(parameter +(parameter .B \-\-LightColor for scanimage). Sets the color of the light source. Possible values: .RS @@ -298,7 +298,7 @@ for scanimage). Sets the color of the light source. Possible values: .br .B blue .RE -The default value is +The default value is .B white. This option is only available in scan modes lineart color and color. @@ -310,75 +310,75 @@ be opened and closed, even if the jammed paper can be removed without opening the maintenance cover. Otherwise, the error condition cannot be cleared. .SH CONFIGURATION -The contents of the +The contents of the .I sharp.conf -file is a list of options and device names that correspond to Sharp +file is a list of options and device names that correspond to Sharp scanners. Empty lines and lines beginning with a hash mark (#) are ignored. See sane\-scsi(5) for details about device names. .PP Lines setting an option start with the key word .B option, followed by the option's name and the option's value. At present, three -options are defined: -.B buffers, buffersize, +options are defined: +.B buffers, buffersize, and -.B readqueue. +.B readqueue. .PP -Options defined at the start of +Options defined at the start of .I sharp.conf apply to all devices; options defined after a device name apply to this device. .PP -The options +The options .B buffers and .B readqueue are only significant if the backend has been compiled -so that for each scan a second process is forked (switch +so that for each scan a second process is forked (switch .B USE_FORK -in +in .I sharp.c ). This process reads the scan data from the scanner and writes this data into a block of shared memory. -The parent process reads the data from this memory block and delivers it -to the frontend. The options control the size and usage of this shared +The parent process reads the data from this memory block and delivers it +to the frontend. The options control the size and usage of this shared memory block. .PP .B option buffers -defines the number of buffers used. The smallest number allowed is 2. +defines the number of buffers used. The smallest number allowed is 2. .PP .B option buffersize -defines the size of one buffer. Since each buffer is filled with a +defines the size of one buffer. Since each buffer is filled with a single read command sent to the scanner, its size is limited automatically to the size allowed by the operating system or by the Sane SCSI library for SCSI read commands. A buffer size of 128 kB or 256 kB is recommended for scan resolutions of 300 dpi and above. .PP -.B option readqueue +.B option readqueue defines how many read commands to be sent to the scanner -are queued. At present, the Sane SCSI library supports queued read -commands only for for Linux. For other operating systems, +are queued. At present, the Sane SCSI library supports queued read +commands only for for Linux. For other operating systems, .B option readqueue -should be set to 0. For Linux, +should be set to 0. For Linux, .B option readqueue should be set to 2. Larger values than 2 for .B option readqueue are not reasonable in most cases. .B option buffers -should be greater than +should be greater than .B option readqueue. .SH Performance Considerations This section focuses on the problem of stops of the scanner's carriage -during a scan. Carriage stops happen mainly with the JX-250. This scanner -has obviously only a small internal buffer compared to its speed. That -means that the backend must read the data as fast as possible from the -scanner in order to avoid carriage stops. +during a scan. Carriage stops happen mainly with the JX-250. This scanner +has obviously only a small internal buffer compared to its speed. That +means that the backend must read the data as fast as possible from the +scanner in order to avoid carriage stops. .PP -Even the JX-250 needs only less than 10 seconds for a 400 dpi A4 gray -scale scan, which results in a data transfer rate of more than 1.6 MB -per second. This means that the data produced by the scanner must be +Even the JX-250 needs only less than 10 seconds for a 400 dpi A4 gray +scale scan, which results in a data transfer rate of more than 1.6 MB +per second. This means that the data produced by the scanner must be processed fairly fast. Due to the small internal buffer of the JX-250, the backend must issue a read request for the next data block as soon as possible after reading a block of data in order to avoid carriage @@ -395,25 +395,25 @@ Stops of the carriage can be caused by the following reasons: .PP .RE Too much "traffic" on the SCSI bus: This happens for example, if hard disks -are connected to the same SCSI bus as the scanner, and when data transfer +are connected to the same SCSI bus as the scanner, and when data transfer from/to these hard disks requires a considerable part of the SCSI bandwidth -during a scan. If this is the case, you should consider to connect the +during a scan. If this is the case, you should consider to connect the scanner to a separate SCSI adapter. .PP Slow responses by the backend to the scanner: Unfortunately, Unix-like operating systems generally have no real time capabilities. Thus there is no guarantee that the backend is under any circumstances able to communicate with the scanner as fast as required. To minimize this -problem, the backend should be compiled so that a separate reader process +problem, the backend should be compiled so that a separate reader process is forked: Make sure that .B USE_FORK -is defined when you compile +is defined when you compile .I sharp.c. If slow responses of the backend remain to be problem, you could try to -reduce the load of the system. Even while the backend and the reader -process need only a minor amount of processor time, other running +reduce the load of the system. Even while the backend and the reader +process need only a minor amount of processor time, other running processes can cause an increase in the time delay between two time -slices given to the reader process. On slower systems, such an +slices given to the reader process. On slower systems, such an increased delay can be enough to cause a carriage stop with the JX-250. For Linux, the usage of the SG driver version 2.1.36 or above is recommended, because it supports, in combination with @@ -424,20 +424,20 @@ This queueing implementation, combined with a buffer size of at least Slow processing of the scan data: An example for this situation is the access to the scanner via a 10 MBit Ethernet, which is definitely too slow to transfer the scan data as fast as they are produced by the -scanner. If you have enough memory available, you can increase +scanner. If you have enough memory available, you can increase .B option buffers, -so that an entire image can be stored in these buffers. +so that an entire image can be stored in these buffers. .PP In order to see, if the backend is too slow or if the further processing of the data is too slow, set the environment variable .B SANE_DEBUG_SHARP to 1. When a scan is finished, the backend writes the line "buffer full -conditions: +conditions: .I nn" to stderr. If .I nn is zero, carriage stops are caused by too slow responses of the backend -or too much "traffic" on the SCSI bus. If +or too much "traffic" on the SCSI bus. If .I nn is greater than zero, the backend had to wait .I nn @@ -469,21 +469,21 @@ levels reduce verbosity. 1. ADF Mode .RS After several ADF scans, the scanner moves the carriage back to the idle -position and back to ADF scan position, before a scan starts. We do not -know, if this is a problem of the scanner, or if this is a bug of the +position and back to ADF scan position, before a scan starts. We do not +know, if this is a problem of the scanner, or if this is a bug of the backend. At present, the scanner must power off and on to stop this annoying behaviour. .RE 2. Threshold level does not work (only JX-610) .PP -3. The maximum resolution is limited to 600 dpi(JX-610 supported +3. The maximum resolution is limited to 600 dpi(JX-610 supported to 1200 dpi) resp. 400 dpi (JX-250) .PP 4. If the JX250 is used with an ADF, the following situation can occur: After several scans, the scanner moves, after loading a new sheet of paper, the carriage to the idle position, and then back to the position used for ADF -scans. This happens for +scans. This happens for .I every scan, in contrast to the calibration, which is done after 10 scans. (For the |