34 const unsigned char *buf)
41 if (!
png.true_color) {
44 for (j = j0; j < j1; j++) {
47 for (i = i0; i < i1; i++) {
49 unsigned int k = buf[j * ncols + i];
50 unsigned int *p = &
png.grid[y *
png.width +
x];
52 if (k > (
unsigned int)threshold)
53 *p =
png.current_color;
63 for (j = j0; j < j1; j++) {
66 for (i = i0; i < i1; i++) {
68 unsigned int k = buf[j * ncols + i];
69 unsigned int *p = &
png.grid[y *
png.width +
x];
71 unsigned int a,
r,
g,
b;
75 a = (a0 * (255 - k) + a1 * k) / 255;
76 r = (r0 * (255 - k) + r1 * k) / 255;
77 g = (g0 * (255 - k) + g1 * k) / 255;
78 b = (b0 * (255 - k) + b1 * k) / 255;