https://github.com/ImageMagick/ImageMagick/issues/588

diff --git a/coders/cip.c b/coders/cip.c
index 0f2912f3f50c1f6706ca15bbdaf738f72f4a4899..fdbc521865083f56a2efc442a2b2f57fedfee6c0 100644 (file)
--- a/coders/cip.c
+++ b/coders/cip.c
@@ -234,22 +234,22 @@ static MagickBooleanType WriteCIPImage(const ImageInfo *image_info,Image *image,
     for (x=0; x < ((ssize_t) image->columns-3); x+=4)
     {
       byte=(unsigned char)
-        ((((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+3))/QuantumRange) & 0x03) << 6) |
-         (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+2))/QuantumRange) & 0x03) << 4) |
-         (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+1))/QuantumRange) & 0x03) << 2) |
-         (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+0))/QuantumRange) & 0x03) << 0));
+        ((((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+3*GetPixelChannels(image)))/QuantumRange) & 0x03) << 6) |
+         (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+2*GetPixelChannels(image)))/QuantumRange) & 0x03) << 4) |
+         (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+1*GetPixelChannels(image)))/QuantumRange) & 0x03) << 2) |
+         (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+0*GetPixelChannels(image)))/QuantumRange) & 0x03) << 0));
       (void) FormatLocaleString(buffer,MagickPathExtent,"%02x",byte);
       (void) WriteBlobString(image,buffer);
-      p+=4;
+      p+=GetPixelChannels(image);
     }
     if ((image->columns % 4) != 0)
       {
         i=(ssize_t) image->columns % 4;
         byte=(unsigned char)
-          ((((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+MagickMin(i,3)))/QuantumRange) & 0x03) << 6) |
-           (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+MagickMin(i,2)))/QuantumRange) & 0x03) << 4) |
-           (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+MagickMin(i,1)))/QuantumRange) & 0x03) << 2) |
-           (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+MagickMin(i,0)))/QuantumRange) & 0x03) << 0));
+          ((((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+MagickMin(i,3)*GetPixelChannels(image)))/QuantumRange) & 0x03) << 6) |
+           (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+MagickMin(i,2)*GetPixelChannels(image)))/QuantumRange) & 0x03) << 4) |
+           (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+MagickMin(i,1)*GetPixelChannels(image)))/QuantumRange) & 0x03) << 2) |
+           (((size_t) (3*ClampToQuantum(GetPixelLuma(image,p+MagickMin(i,0)*GetPixelChannels(image)))/QuantumRange) & 0x03) << 0));
         (void) FormatLocaleString(buffer,MagickPathExtent,"%02x",~byte);
         (void) WriteBlobString(image,buffer);
       }