#28304 [Asn]: ImageFilter, no bounds check processing image per-pixel: creates a black border

ID: 28304 User updated by: ken at sonicwizardry dot com Reported By: ken at sonicwizardry dot com Status: Assigned Bug Type: GD related Operating System: Linux PHP Version: 5.0.0RC2 Assigned To: pajoye New Comment: Pierre, IMG_FILTER_GAUSSIAN_BLUR Best, Ken Previous Comments: ------------------------------------------------------------------------ [2004-05-07 00:12:55] pajoye@php.net the patch is ok, however I prefer to do the check only once outside the loops. Let me check first if it's possible for this filter. Which one are using? Pierre ------------------------------------------------------------------------ [2004-05-06 18:50:38] ken at sonicwizardry dot com Description: ------------ Running ImageFilter on an image creates a black border around the edge because it references non-existing pixels off of the image (beyond image size). Bounds check/clamp added to convolution loop. Code DIFF is below: File path: ext/gd/libgd/gd.c 3607,3610c3607,3614 < pxl = f(srcback, x-(3>>1)+i, y-(3>>1)+j); < new_r += (float)gdImageRed(srcback, pxl) * filter[j][i]; < new_g += (float)gdImageGreen(srcback, pxl) * filter[j][i]; < new_b += (float)gdImageBlue(srcback, pxl) * filter[j][i]; --- > int ix = x-(3>>1)+i; > int iy = y-(3>>1)+j; > ix = (ix>=src->sx)?src->sx-1 : ((ix<0)?0:ix); > iy = (iy>=src->sy)?src->sy-1 : ((iy<0)?0:iy); > pxl = f(srcback, ix, iy); > new_r += (float)gdImageRed(srcback, pxl) * filter[j][i]; > new_g += (float)gdImageGreen(srcback, pxl) * filter[j][i]; > new_b += (float)gdImageBlue(srcback, pxl) * filter[j][i]; Hope this helps! -Ken Post Jr. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=28304&edit=1