Changeset 2670 for libpipi/trunk/pipi/dither/dbs.c

Timestamp:

08/04/08 19:23:59 (5 years ago)

Author:

sam

Message:

• Dithering algorithms no longer modify the original image.

File:

• libpipi/trunk/pipi/dither/dbs.c (modified) (4 diffs)

libpipi/trunk/pipi/dither/dbs.c

@@ -36 +36 @@
  * guaranteed stop condition here. */
 
-pipi_image_t *pipi_dither_dbs(pipi_image_t *src)
+pipi_image_t *pipi_dither_dbs(pipi_image_t *img)
 {
     double kernel[NN * NN];
     double t = 0.;
-    pipi_image_t *dst, *tmp1, *tmp2;
-    pipi_pixels_t *srcp, *dstp, *tmp1p, *tmp2p;
+    pipi_image_t *src, *dst, *tmp1, *tmp2;
+    pipi_pixels_t *dstp, *tmp1p, *tmp2p;
     int *changelist;
-    float *srcdata, *dstdata, *tmp1data, *tmp2data;
+    float *dstdata, *tmp1data, *tmp2data;
     int i, j, x, y, w, h, cw, ch;
 
@@ -62 +62 @@
             kernel[j * NN + i] /= t;
 
-    w = src->w;
-    h = src->h;
+    w = img->w;
+    h = img->h;
 
     cw = (w + CELL - 1) / CELL;
@@ -70 +70 @@
     memset(changelist, 0, cw * ch * sizeof(int));
 
-    srcp = pipi_getpixels(src, PIPI_PIXELS_Y_F);
-    srcdata = (float *)srcp->pixels;
+    src = pipi_copy(img);
+    pipi_getpixels(src, PIPI_PIXELS_Y_F);
 
     tmp1 = pipi_convolution(src, NN, NN, kernel);
@@ -77 +77 @@
     tmp1data = (float *)tmp1p->pixels;
 
-    /* The initial dither is an empty image. So is its blurred version,
-     * but I leave the pipi_convolution() call here in case we choose
-     * to change the way to create the initial dither. */
-    dst = pipi_new(w, h);
+    dst = pipi_dither_floydsteinberg(src, PIPI_SCAN_SERPENTINE);
     dstp = pipi_getpixels(dst, PIPI_PIXELS_Y_F);
     dstdata = (float *)dstp->pixels;
 
-    for(y = 0; y < h; y++)
-        for(x = 0; x < w; x++)
-            dstdata[y * w + x] = srcdata[y * w + x] > 0.5 ? 1.0 : 0.0;
+    pipi_free(src);
 
     tmp2 = pipi_convolution(dst, NN, NN, kernel);