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Diffstat (limited to 'cupsfilters/testdither.c')
| -rw-r--r-- | cupsfilters/testdither.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/cupsfilters/testdither.c b/cupsfilters/testdither.c new file mode 100644 index 000000000..be2eaf203 --- /dev/null +++ b/cupsfilters/testdither.c @@ -0,0 +1,186 @@ +/* + * Dither test program for CUPS. + * + * Try the following: + * + * testdither 0 255 > filename.ppm + * testdither 0 127 255 > filename.ppm + * testdither 0 85 170 255 > filename.ppm + * testdither 0 63 127 170 198 227 255 > filename.ppm + * testdither 0 210 383 > filename.ppm + * testdither 0 82 255 > filename.ppm + * + * Copyright 2007-2011 by Apple Inc. + * Copyright 1993-2005 by Easy Software Products. + * + * These coded instructions, statements, and computer programs are the + * property of Apple Inc. and are protected by Federal copyright + * law. Distribution and use rights are outlined in the file "COPYING" + * which should have been included with this file. + * + * Contents: + * + * main() - Test dithering and output a PPM file. + * usage() - Show program usage... + */ + +/* + * Include necessary headers. + */ + +#include "driver.h" +#include <config.h> +#include <string.h> +#include <ctype.h> + + +/* + * Local functions... + */ + +void usage(void); + + +/* + * 'main()' - Test dithering and output a PPM file. + */ + +int /* O - Exit status */ +main(int argc, /* I - Number of command-line arguments */ + char *argv[]) /* I - Command-line arguments */ +{ + int x, y; /* Current coordinate in image */ + short line[512]; /* Line to dither */ + unsigned char pixels[512], /* Dither pixels */ + *pixptr; /* Pointer in line */ + int output; /* Output pixel */ + cups_lut_t *lut; /* Dither lookup table */ + cups_dither_t *dither; /* Dither state */ + int nlutvals; /* Number of lookup values */ + float lutvals[16]; /* Lookup values */ + int pixvals[16]; /* Pixel values */ + + + /* + * See if we have lookup table values on the command-line... + */ + + if (argc > 1) + { + /* + * Yes, collect them... + */ + + nlutvals = 0; + + for (x = 1; x < argc; x ++) + if (isdigit(argv[x][0]) && nlutvals < 16) + { + pixvals[nlutvals] = atoi(argv[x]); + lutvals[nlutvals] = atof(argv[x]) / 255.0; + nlutvals ++; + } + else + usage(); + + /* + * See if we have at least 2 values... + */ + + if (nlutvals < 2) + usage(); + } + else + { + /* + * Otherwise use the default 2-entry LUT with values of 0 and 255... + */ + + nlutvals = 2; + lutvals[0] = 0.0; + lutvals[1] = 1.0; + pixvals[0] = 0; + pixvals[1] = 255; + } + + /* + * Create the lookup table and dither state... + */ + + lut = cupsLutNew(nlutvals, lutvals); + dither = cupsDitherNew(512); + + /* + * Put out the PGM header for a raw 256x256x8-bit grayscale file... + */ + + puts("P5\n512\n512\n255"); + + /* + * Dither 512 lines, which are written out in 256 image lines... + */ + + for (y = 0; y < 512; y ++) + { + /* + * Create the grayscale data for the current line... + */ + + for (x = 0; x < 512; x ++) + line[x] = 4095 * ((y / 32) * 16 + x / 32) / 255; + + /* + * Dither the line... + */ + + cupsDitherLine(dither, lut, line, 1, pixels); + + if (y == 0) + { + fputs("DEBUG: pixels =", stderr); + for (x = 0; x < 512; x ++) + fprintf(stderr, " %d", pixels[x]); + fputs("\n", stderr); + } + + /* + * Add or set the output pixel values... + */ + + for (x = 0, pixptr = pixels; x < 512; x ++, pixptr ++) + { + output = 255 - pixvals[*pixptr]; + + if (output < 0) + putchar(0); + else + putchar(output); + } + } + + /* + * Free the dither state and lookup table... + */ + + cupsDitherDelete(dither); + cupsLutDelete(lut); + + /* + * Return with no errors... + */ + + return (0); +} + + +/* + * 'usage()' - Show program usage... + */ + +void +usage(void) +{ + puts("Usage: testdither [val1 val2 [... val16]] >filename.ppm"); + exit(1); +} + |