kopia lustrzana https://gitlab.com/sane-project/backends
enable dynamic rasterization for lineart scans
- use emulated lineart mode to apply binarize function pulled from the epjitsu backend (by m. allan noah).merge-requests/1/head
Stphane Voltz
rodzic
0cc0532505
commit
f42cb07d8d
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@ -2,11 +2,14 @@
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Copyright (C) 2003, 2004 Henning Meier-Geinitz <henning@meier-geinitz.de>
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Copyright (C) 2004, 2005 Gerhard Jaeger <gerhard@gjaeger.de>
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Copyright (C) 2004-2009 Stéphane Voltz <stef.dev@free.fr>
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Copyright (C) 2004-2010 Stéphane Voltz <stef.dev@free.fr>
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Copyright (C) 2005-2009 Pierre Willenbrock <pierre@pirsoft.dnsalias.org>
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Copyright (C) 2006 Laurent Charpentier <laurent_pubs@yahoo.com>
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Copyright (C) 2007 Luke <iceyfor@gmail.com>
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Dynamic rasterization code was taken from the epjistsu backend by
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m. allan noah <kitno455 at gmail dot com>
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This file is part of the SANE package.
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This program is free software; you can redistribute it and/or
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@ -164,6 +167,12 @@ static const SANE_Range threshold_percentage_range = {
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SANE_FIX (1) /* quantization */
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};
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static const SANE_Range threshold_curve_range = {
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0, /* minimum */
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127, /* maximum */
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1 /* quantization */
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};
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/* ------------------------------------------------------------------------ */
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/* functions calling ASIC specific functions */
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/* ------------------------------------------------------------------------ */
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@ -3986,6 +3995,89 @@ genesys_wait_not_moving (Genesys_Device * dev, int mseconds)
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}
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#endif
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/* Function to build a lookup table (LUT), often
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used by scanners to implement brightness/contrast/gamma
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or by backends to speed binarization/thresholding
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offset and slope inputs are -127 to +127
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slope rotates line around central input/output val,
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0 makes horizontal line
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pos zero neg
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. x . . x
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. x . . x
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out . x .xxxxxxxxxxx . x
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. x . . x
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....x....... ............ .......x....
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in in in
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offset moves line vertically, and clamps to output range
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0 keeps the line crossing the center of the table
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high low
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. xxxxxxxx .
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. x .
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out x . x
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. . x
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............ xxxxxxxx....
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in in
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out_min/max provide bounds on output values,
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useful when building thresholding lut.
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0 and 255 are good defaults otherwise.
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*/
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static SANE_Status
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load_lut (unsigned char * lut,
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int in_bits, int out_bits,
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int out_min, int out_max,
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int slope, int offset)
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{
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SANE_Status ret = SANE_STATUS_GOOD;
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int i, j;
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double shift, rise;
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int max_in_val = (1 << in_bits) - 1;
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int max_out_val = (1 << out_bits) - 1;
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unsigned char * lut_p = lut;
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DBG (DBG_proc, "load_lut: start\n");
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/* slope is converted to rise per unit run:
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* first [-127,127] to [-1,1]
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* then multiply by PI/2 to convert to radians
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* then take the tangent (T.O.A)
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* then multiply by the normal linear slope
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* because the table may not be square, i.e. 1024x256*/
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rise = tan((double)slope/127 * M_PI/2) * max_out_val / max_in_val;
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/* line must stay vertically centered, so figure
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* out vertical offset at central input value */
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shift = (double)max_out_val/2 - (rise*max_in_val/2);
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/* convert the user offset setting to scale of output
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* first [-127,127] to [-1,1]
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* then to [-max_out_val/2,max_out_val/2]*/
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shift += (double)offset / 127 * max_out_val / 2;
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for(i=0;i<=max_in_val;i++){
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j = rise*i + shift;
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if(j<out_min){
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j=out_min;
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}
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else if(j>out_max){
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j=out_max;
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}
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*lut_p=j;
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lut_p++;
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}
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DBG (DBG_proc, "load_lut: finish\n");
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return ret;
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}
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/* ------------------------------------------------------------------------ */
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/* High level (exported) functions */
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/* ------------------------------------------------------------------------ */
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@ -4267,6 +4359,19 @@ genesys_start_scan (Genesys_Device * dev)
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return status;
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}
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/* build look up table for dynamic lineart */
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if(dev->settings.dynamic_lineart==SANE_TRUE)
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{
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status = load_lut(dev->lineart_lut, 8, 8, 50, 205,
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dev->settings.threshold_curve,
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dev->settings.threshold-127);
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if (status != SANE_STATUS_GOOD)
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{
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DBG (DBG_error, "genesys_start_scan: failed to build lut\n");
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return status;
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}
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}
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status = dev->model->cmd_set->init_regs_for_scan (dev);
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if (status != SANE_STATUS_GOOD)
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{
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@ -5010,10 +5115,12 @@ Problems with the first approach:
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bytes = dst_lines * dev->settings.pixels * channels;
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status = genesys_gray_lineart (work_buffer_src, destination,
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status = genesys_gray_lineart (dev,
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work_buffer_src,
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destination,
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dev->settings.pixels,
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channels,
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dst_lines, dev->settings.threshold);
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dst_lines,
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dev->settings.threshold);
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if (status != SANE_STATUS_GOOD)
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{
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DBG (DBG_error,
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@ -5173,7 +5280,12 @@ calc_parameters (Genesys_Scanner * s)
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/* dynamic lineart */
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s->dev->settings.dynamic_lineart =
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s->val[OPT_DYNAMIC_LINEART].w == SANE_TRUE;
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DBG (DBG_io2, "dynamic_lineart=%d\n",s->dev->settings.dynamic_lineart);
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/* threshold curve for dynamic ratserization */
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if(s->dev->settings.dynamic_lineart==SANE_TRUE)
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s->dev->settings.threshold_curve=s->val[OPT_THRESHOLD_CURVE].w;
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else
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s->dev->settings.threshold_curve=0;
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return status;
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}
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@ -5446,6 +5558,16 @@ init_options (Genesys_Scanner * s)
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s->opt[OPT_THRESHOLD].constraint.range = &threshold_percentage_range;
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s->val[OPT_THRESHOLD].w = SANE_FIX (50);
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/* BW threshold curve */
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s->opt[OPT_THRESHOLD_CURVE].name = "threshold-curve";
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s->opt[OPT_THRESHOLD_CURVE].title = SANE_I18N ("Threshold curve");
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s->opt[OPT_THRESHOLD_CURVE].desc = SANE_I18N ("Dynamic threshold curve, from light to dark, normally 50-65");
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s->opt[OPT_THRESHOLD_CURVE].type = SANE_TYPE_INT;
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s->opt[OPT_THRESHOLD_CURVE].unit = SANE_UNIT_NONE;
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s->opt[OPT_THRESHOLD_CURVE].constraint_type = SANE_CONSTRAINT_RANGE;
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s->opt[OPT_THRESHOLD_CURVE].constraint.range = &threshold_curve_range;
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s->val[OPT_THRESHOLD_CURVE].w = 50;
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/* dynamic linart */
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s->opt[OPT_DYNAMIC_LINEART].name = "dynamic-lineart";
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s->opt[OPT_DYNAMIC_LINEART].title = SANE_I18N ("Dynamic lineart");
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@ -6356,6 +6478,7 @@ get_option_value (Genesys_Scanner * s, int option, void *val)
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case OPT_BR_X:
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case OPT_BR_Y:
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case OPT_THRESHOLD:
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case OPT_THRESHOLD_CURVE:
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case OPT_DYNAMIC_LINEART:
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case OPT_DISABLE_INTERPOLATION:
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case OPT_LAMP_OFF_TIME:
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@ -6466,6 +6589,7 @@ set_option_value (Genesys_Scanner * s, int option, void *val,
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case OPT_RESOLUTION:
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case OPT_BIT_DEPTH:
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case OPT_THRESHOLD:
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case OPT_THRESHOLD_CURVE:
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case OPT_DYNAMIC_LINEART:
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case OPT_DISABLE_INTERPOLATION:
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case OPT_PREVIEW:
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@ -6489,12 +6613,14 @@ set_option_value (Genesys_Scanner * s, int option, void *val,
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if (strcmp (s->val[option].s, SANE_VALUE_SCAN_MODE_LINEART) == 0)
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{
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ENABLE (OPT_THRESHOLD);
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ENABLE (OPT_THRESHOLD_CURVE);
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DISABLE (OPT_BIT_DEPTH);
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ENABLE (OPT_COLOR_FILTER);
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}
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else
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{
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DISABLE (OPT_THRESHOLD);
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DISABLE (OPT_THRESHOLD_CURVE);
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if (strcmp (s->val[option].s, SANE_VALUE_SCAN_MODE_GRAY) == 0)
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{
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ENABLE (OPT_COLOR_FILTER);
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@ -92,6 +92,7 @@ enum Genesys_Option
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OPT_EXTRAS_GROUP,
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OPT_LAMP_OFF_TIME,
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OPT_THRESHOLD,
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OPT_THRESHOLD_CURVE,
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OPT_DYNAMIC_LINEART,
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OPT_DISABLE_INTERPOLATION,
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OPT_COLOR_FILTER,
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@ -89,30 +89,89 @@ genesys_reverse_bits(
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return SANE_STATUS_GOOD;
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}
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/**
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* uses the threshold/threshold_curve to control software binarization
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* This code was taken from the epjistsu backend by m. allan noah <kitno455 at gmail dot com>
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* @param dev device set up for the scan
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* @param src pointer to raw data
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* @param dst pointer where to store result
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* @param width width of the processed line
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* */
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static SANE_Status
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binarize_line(Genesys_Device * dev, uint8_t *src, uint8_t *dst, int width)
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{
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int j, windowX, sum = 0;
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int thresh;
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int offset, addCol, dropCol;
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unsigned char mask;
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/* ~1mm works best, but the window needs to have odd # of pixels */
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windowX = 6 * dev->settings.xres / 150;
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if (!(windowX % 2))
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windowX++;
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/* second, prefill the sliding sum */
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for (j = 0; j < windowX; j++)
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sum += src[j];
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/* third, walk the input buffer, update the sliding sum, */
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/* determine threshold, output bits */
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for (j = 0; j < width; j++)
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{
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/* output image location */
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offset = j % 8;
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mask = 0x80 >> offset;
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thresh = dev->settings.threshold;
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/* move sum/update threshold only if there is a curve */
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if (dev->settings.threshold_curve)
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{
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addCol = j + windowX / 2;
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dropCol = addCol - windowX;
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if (dropCol >= 0 && addCol < width)
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{
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sum -= src[dropCol];
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sum += src[addCol];
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}
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thresh = dev->lineart_lut[sum / windowX];
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}
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/* use average to lookup threshold */
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if (src[j] > thresh)
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*dst &= ~mask; /* white */
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else
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*dst |= mask; /* black */
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if (offset == 7)
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dst++;
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}
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return SANE_STATUS_GOOD;
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}
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/**
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* software lineart using data from a 8 bit gray scan. We assume true gray
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* or monochrome scan as input.
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*/
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static SANE_Status
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genesys_gray_lineart(
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Genesys_Device *dev,
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uint8_t *src_data,
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uint8_t *dst_data,
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size_t pixels,
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size_t channels,
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size_t lines,
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uint8_t threshold)
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{
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size_t x,y,c,b;
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size_t y;
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DBG ( DBG_io2, "genesys_gray_lineart: converting %d lines of %d pixels\n", lines, pixels);
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for(y = 0; y < lines; y++) {
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for(x = 0; x < pixels; x+=8) {
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for(c = 0; c < channels; c++)
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*(dst_data + c) = 0;
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for(b = 0; b < 8 && x+b < pixels; b++) {
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for(c = 0; c < channels; c++) {
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if (*src_data++ < threshold)
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*(dst_data + c) |= (0x80 >> b);
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}
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}
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dst_data += channels;
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}
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}
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for(y = 0; y < lines; y++)
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{
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binarize_line(dev, src_data+y*pixels, dst_data, pixels);
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dst_data += pixels/8;
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}
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return SANE_STATUS_GOOD;
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}
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@ -503,6 +503,9 @@ typedef struct
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/**> lineart threshold */
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int threshold;
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/**> lineart threshold curve for dynamic rasterization */
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int threshold_curve;
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/**> Disable interpolation for xres<yres*/
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int disable_interpolation;
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@ -581,7 +584,7 @@ struct Genesys_Device
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SANE_Int lamp_off_time;
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SANE_Bool read_active;
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SANE_Bool document; /* for sheetfed scanner's, is TRUE when there
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SANE_Bool document; /**> for sheetfed scanner's, is TRUE when there
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is a document in the scanner */
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Genesys_Buffer read_buffer;
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@ -596,6 +599,9 @@ struct Genesys_Device
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size_t wpl; /* asic's word per line */
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Genesys_Current_Setup current_setup; /* contains the real used values */
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/**> look up table used in dynamic rasterization */
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unsigned char lineart_lut[256];
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Genesys_Calibration_Cache *calibration_cache;
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