...
diff --git a/coders/dpx.c b/coders/dpx.c
index ab8fc81..9959ffc 100644
--- a/coders/dpx.c
+++ b/coders/dpx.c
@@ -1494,6 +1494,7 @@
i;
size_t
+ channels,
extent;
ssize_t
@@ -1559,7 +1560,12 @@
offset+=WriteBlobLong(image,dpx.file.image_offset);
(void) strncpy(dpx.file.version,"V2.0",sizeof(dpx.file.version)-1);
offset+=WriteBlob(image,8,(unsigned char *) &dpx.file.version);
- dpx.file.file_size=(unsigned int) (3U*image->columns*image->rows+
+ channels=1;
+ if (IsImageGray(image) == MagickFalse)
+ channels=3;
+ if (image->alpha_trait != UndefinedPixelTrait)
+ channels++;
+ dpx.file.file_size=(unsigned int) (channels*image->columns*image->rows+
dpx.file.image_offset);
offset+=WriteBlobLong(image,dpx.file.file_size);
dpx.file.ditto_key=1U; /* new frame */
