Hi. I'm looking at the ImageMagick 6.3.7 source code,
wand/magick-image.c, and see
| MagickExport MagickBooleanType MagickSegmentImage(MagickWand *wand,
| const ColorspaceType colorspace,const MagickBooleanType verbose,
| const double cluster_threshold,const double smooth_threshold)
| {
| MagickBooleanType
| status;
|
| assert(wand != (MagickWand *) NULL);
| assert(wand->signature == WandSignature);
| if (wand->debug != MagickFalse)
| (void) LogMagickEvent(WandEvent,GetMagickModule(),"%s",wand->name);
| if (wand->images == (Image *) NULL)
| ThrowWandException(WandError,"ContainsNoImages",wand->name);
| status=SegmentImage(wand->images,colorspace,verbose,cluster_threshold,
| smooth_threshold);
| if (status == MagickFalse)
| InheritException(wand->exception,&wand->images->exception);
| return(MagickFalse);
| }
Shouldn't that last line be
return(status);
? As written, the call always fails, even if it doesn't.
(Insert obligatory apologies if this has come up before - I'm new and
did just a cursory seearch.)
While we're on the subject of boolean algebra, in magick/resize.c,
ResizeImage(), there are calls to two sequential filtering functions:
| status=HorizontalFilter(resize_filter,image,filter_image,x_factor,span,
| &quantum,exception);
| status|=VerticalFilter(resize_filter,filter_image,resize_image,y_factor,
| span,&quantum,exception);
I read that as "first we squish the image in one direction, then in the other."
That status is later used to figure out whether an allocation failed:
| if (status == MagickFalse)
| {
| resize_image=DestroyImage(resize_image);
| ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
| }
Since MagickFalse is 0 (as of magick-type.h), status will only be false
if *both* HorizontalFilter() *and* VerticalFilter() suffered allocation
failures. Is that really what was intended? Or did the author mean &= ?
Or am I misinterpreting the way I'm supposed to detect and handle errors?
Thanks!
Jutta <[EMAIL PROTECTED]>
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