adjust GIF alpha threshold

see https://github.com/libvips/libvips/discussions/2604
2021-12-31 20:20:56 +00:00 · 2021-12-31 20:20:56 +00:00 · f75b3c1ee9
parent d3f77e4433
commit f75b3c1ee9
2 changed files with 2 additions and 1 deletions
--- a/1
+++ b/1
@ -6,6 +6,7 @@
 - change default frame delay for GIFs from 1s to 0.1s
 - remove stray trailing comma from iiif3 dirnames [whalehub]
 - fix TTF load [chregu]
+- revise GIF save alpha threshold [jfcalvo]

 21/11/21 started 8.12.1
 - fix insert [chregu]
--- a/libvips/foreign/cgifsave.c
+++ b/libvips/foreign/cgifsave.c
@ -188,7 +188,7 @@ vips_foreign_save_cgif_write_frame( VipsForeignSaveCgif *cgif )
 	 */
 	p = frame_bytes;
 	for( i = 0; i < n_pels; i++ ) {
-		p[3] = p[3] > 128 ? 255 : 0;
+		p[3] = p[3] >= 128 ? 255 : 0;
 		p += 4;
 	}