ImageGear for C and C++ on Windows v19.9 - Updated
IG_ISIS_TAG_DITHER_PATTERN1
Custom dither pattern data. 0x0548 ∙ 1352
For scanners that support downloadable dithering patterns, IG_ISIS_TAG_DITHER_PATTERN1 specifies the data for each element of the downloadable dithering pattern.
IG_ISIS_TAG_TYPE_LONG
Drivers for scanner that support at least one downloadable dither pattern.
An array of values, each with valid choices in the range of 0 - 255, that specify the data for a rectangular downloadable dither pattern. This tag has a number of elements equal to the product of IG_ISIS_TAG_DITHER_LENGTH1 and IG_ISIS_TAG_DITHER_WIDTH1.
Bayer Dither [64 steps]
8 8
4 129 35 161 12 137 43 169
192 67 224 98 200 75 231 106
51 177 20 145 59 184 27 153
239 114 208 82 247 122 216 90
16 141 47 173 8 133 39 165
204 78 235 110 196 71 228 102
63 188 31 157 55 180 24 149
251 126 220 94 243 118 212 86
The first line of the file is the name of the dither pattern. The second line specifies the width and then length of the dither pattern. The rest of the file contains the actual dither values.
To create a downloadable dithering pattern, establish a width and length of the pattern, then fill in the values for each element of the pattern by calling IG_ISIS_tag_set_long. You can also let the user select an existing dither file by calling IG_ISIS_drv_read_dither_file. For more information on downloadable dither patterns, consult the documentation supplied with scanners that support downloadable dither patterns.