Cast to origin pixel format after premultiplication

vips/vips.c

@@ -200,13 +200,14 @@ vips_resize_go(VipsImage *in, VipsImage **out, double wscale, double hscale) {
   VipsBandFormat format = vips_band_format(in);
 
   VipsImage *base = vips_image_new();
-  VipsImage **t = (VipsImage **) vips_object_local_array(VIPS_OBJECT(base), 3);
+  VipsImage **t = (VipsImage **) vips_object_local_array(VIPS_OBJECT(base), 4);
 
   int res =
     vips_premultiply(in, &t[0], NULL) ||
-    vips_resize(t[0], &t[1], wscale, "vscale", hscale, NULL) ||
-    vips_unpremultiply(t[1], &t[2], NULL) ||
-    vips_cast(t[2], out, format, NULL);
+    vips_cast(t[0], &t[1], format, NULL) ||
+    vips_resize(t[1], &t[2], wscale, "vscale", hscale, NULL) ||
+    vips_unpremultiply(t[2], &t[3], NULL) ||
+    vips_cast(t[3], out, format, NULL);
 
   clear_image(&base);
 
@@ -306,14 +307,17 @@ vips_apply_filters(VipsImage *in, VipsImage **out, double blur_sigma,
   double sharp_sigma, int pixelate_pixels) {
 
   VipsImage *base = vips_image_new();
-  VipsImage **t = (VipsImage **) vips_object_local_array(VIPS_OBJECT(base), 9);
+  VipsImage **t = (VipsImage **) vips_object_local_array(VIPS_OBJECT(base), 10);
 
   VipsInterpretation interpretation = in->Type;
   VipsBandFormat format = in->BandFmt;
   gboolean premultiplied = FALSE;
 
   if ((blur_sigma > 0 || sharp_sigma > 0) && vips_image_hasalpha(in)) {
-    if (vips_premultiply(in, &t[0], NULL)) {
+    if (
+      vips_premultiply(in, &t[0], NULL) ||
+      vips_cast(t[0], &t[1], format, NULL)
+    ) {
       clear_image(&base);
       return 1;
     }
@@ -323,21 +327,21 @@ vips_apply_filters(VipsImage *in, VipsImage **out, double blur_sigma,
   }
 
   if (blur_sigma > 0.0) {
-    if (vips_gaussblur(in, &t[1], blur_sigma, NULL)) {
+    if (vips_gaussblur(in, &t[2], blur_sigma, NULL)) {
       clear_image(&base);
       return 1;
     }
 
-    in = t[1];
+    in = t[2];
   }
 
   if (sharp_sigma > 0.0) {
-    if (vips_sharpen(in, &t[2], "sigma", sharp_sigma, NULL)) {
+    if (vips_sharpen(in, &t[3], "sigma", sharp_sigma, NULL)) {
       clear_image(&base);
       return 1;
     }
 
-    in = t[2];
+    in = t[3];
   }
 
   pixelate_pixels = VIPS_MIN(pixelate_pixels, VIPS_MAX(in->Xsize, in->Ysize));
@@ -352,46 +356,46 @@ vips_apply_filters(VipsImage *in, VipsImage **out, double blur_sigma,
     th = (int)(VIPS_CEIL((double)h / pixelate_pixels)) * pixelate_pixels;
 
     if (tw > w || th > h) {
-      if (vips_embed(in, &t[3], 0, 0, tw, th, "extend", VIPS_EXTEND_MIRROR, NULL)) {
+      if (vips_embed(in, &t[4], 0, 0, tw, th, "extend", VIPS_EXTEND_MIRROR, NULL)) {
         clear_image(&base);
         return 1;
       }
 
-      in = t[3];
+      in = t[4];
     }
 
     if (
-      vips_shrink(in, &t[4], pixelate_pixels, pixelate_pixels, NULL) ||
-      vips_zoom(t[4], &t[5], pixelate_pixels, pixelate_pixels, NULL)
+      vips_shrink(in, &t[5], pixelate_pixels, pixelate_pixels, NULL) ||
+      vips_zoom(t[5], &t[6], pixelate_pixels, pixelate_pixels, NULL)
     ) {
         clear_image(&base);
         return 1;
     }
 
-    in = t[5];
+    in = t[6];
 
     if (tw > w || th > h) {
-      if (vips_extract_area(in, &t[6], 0, 0, w, h, NULL)) {
+      if (vips_extract_area(in, &t[7], 0, 0, w, h, NULL)) {
           clear_image(&base);
           return 1;
       }
 
-      in = t[6];
+      in = t[7];
     }
   }
 
   if (premultiplied) {
-    if (vips_unpremultiply(in, &t[7], NULL)) {
+    if (vips_unpremultiply(in, &t[8], NULL)) {
       clear_image(&base);
       return 1;
     }
 
-    in = t[7];
+    in = t[8];
   }
 
   int res =
-    vips_colourspace(in, &t[8], interpretation, NULL) ||
-    vips_cast(t[8], out, format, NULL);
+    vips_colourspace(in, &t[9], interpretation, NULL) ||
+    vips_cast(t[9], out, format, NULL);
 
   clear_image(&base);