diff options
Diffstat (limited to 'source/blender/imbuf/intern/scaling.c')
| -rw-r--r-- | source/blender/imbuf/intern/scaling.c | 33 |
1 files changed, 17 insertions, 16 deletions
diff --git a/source/blender/imbuf/intern/scaling.c b/source/blender/imbuf/intern/scaling.c index 807b0c84e90..b308915cd62 100644 --- a/source/blender/imbuf/intern/scaling.c +++ b/source/blender/imbuf/intern/scaling.c @@ -609,34 +609,35 @@ static void shrink_picture_byte( w = (weight1y * weight1x) >> 16; - dst_line1[x].r += (line[0] * w) >> 16; - dst_line1[x].g += (line[1] * w) >> 16; - dst_line1[x].b += (line[2] * w) >> 16; - dst_line1[x].a += (line[3] * w) >> 16; + /* ensure correct rounding, without this you get ugly banding (ton) */ + dst_line1[x].r += (line[0] * w + 32767) >> 16; + dst_line1[x].g += (line[1] * w + 32767) >> 16; + dst_line1[x].b += (line[2] * w + 32767) >> 16; + dst_line1[x].a += (line[3] * w + 32767) >> 16; dst_line1[x].weight += w; w = (weight2y * weight1x) >> 16; - dst_line2[x].r += (line[0] * w) >> 16; - dst_line2[x].g += (line[1] * w) >> 16; - dst_line2[x].b += (line[2] * w) >> 16; - dst_line2[x].a += (line[3] * w) >> 16; + dst_line2[x].r += (line[0] * w + 32767) >> 16; + dst_line2[x].g += (line[1] * w + 32767) >> 16; + dst_line2[x].b += (line[2] * w + 32767) >> 16; + dst_line2[x].a += (line[3] * w + 32767) >> 16; dst_line2[x].weight += w; w = (weight1y * weight2x) >> 16; - dst_line1[x+1].r += (line[0] * w) >> 16; - dst_line1[x+1].g += (line[1] * w) >> 16; - dst_line1[x+1].b += (line[2] * w) >> 16; - dst_line1[x+1].a += (line[3] * w) >> 16; + dst_line1[x+1].r += (line[0] * w + 32767) >> 16; + dst_line1[x+1].g += (line[1] * w + 32767) >> 16; + dst_line1[x+1].b += (line[2] * w + 32767) >> 16; + dst_line1[x+1].a += (line[3] * w + 32767) >> 16; dst_line1[x+1].weight += w; w = (weight2y * weight2x) >> 16; - dst_line2[x+1].r += (line[0] * w) >> 16; - dst_line2[x+1].g += (line[1] * w) >> 16; - dst_line2[x+1].b += (line[2] * w) >> 16; - dst_line2[x+1].a += (line[3] * w) >> 16; + dst_line2[x+1].r += (line[0] * w + 32767) >> 16; + dst_line2[x+1].g += (line[1] * w + 32767) >> 16; + dst_line2[x+1].b += (line[2] * w + 32767) >> 16; + dst_line2[x+1].a += (line[3] * w + 32767) >> 16; dst_line2[x+1].weight += w; x_dst += dx_dst; |