Legacy ImageMagick Discussions Archive

After giving the command "display img.jpg", flipping the image and quitting, I get display: magick/list.c:447: DestroyImageList: Assertion `images->signature == 0xabacadabUL' failed. Aborted (core dumped) Looking what happens, I see that utilities/display.c calls MagickCommandGenesis(...,D...

Do you really want to forget where the PNG was cropped from? Yes. That that information is present is more or less an artifact of the present code. For example, a screenshot of a window does not have the offset information, that info is present only for handselected rectangles. It follows that ther...

The way I myself take interactive screen shots is using XV. Bad for you - xv is commercial, unmaintained since 1995 or so, has hundreds of patches found all over the net, and nothing happens because of license problems. On the other hand, IM has its own interactive screenshot tool, called import. I...

aeb wrote:The screendump is from XGetWindowImage, but it does not always correctly determine which window is on top,

Fixed that. For the patch, see the webpage mentioned in the first post of this thread.

Will investigate further. OK. For me the following diff --- ImageMagick-6.8.0-6/wand/import.c 2011-12-19 02:54:26.000000000 +0100 +++ ImageMagick-6.8.0-6a/wand/import.c 2013-01-10 00:21:19.000000000 +0100 @@ -381,7 +381,7 @@ image_info->density=XGetResourceInstance(resource_database,GetClientName()...

Can you see what problems this would cause? Yes, things would work out-of-the-box. Unheard of. [More seriously - one can discuss usability versus compatibility with previous mistakes. There is no clearcut answer. "Foo --avoid-bug1 --avoid-bug2" is acceptable in Makefiles or other contexts...

So, if I understand correctly, there is no offset bug in either IM or Gimp, but you want to change the default behaviour to save yourself ... You do not understand correctly. (And ad hominem talk is never fruitful.) Gimp is broken. (The old gimp was just broken - it creates a layer and places the i...

If I apply offsets, I see a transparent image, due to the offsets. Zooming out shows me where the real pixels are. If I then "Image | Fit canvas to layers", I can see them. Yes. You have to either ignore offsets or to fit canvas to layers. In other words, you have to get rid of the offset...

snibgo wrote:Can you post a PNG that Gimp doesn't handle properly?

Try http://www.win.tue.nl/~aeb/linux/misc/import/ss0.png (from the page linked to in the first post above).

If I understand correctly, this is pretty much what happens: if the user wants the offsets, don't "+repage"; if the user doesnt want the offsets, use "+repage". Yes, but the default is wrong. By default the user gets a picture that is unusable (in gimp). That is a bug. Import sh...

The PNG encoder assumes that if "page" information is present it should be written in oFFs/vpAg chunks. It really has no way of knowing that the caller has defined them wrong and doesn't really want them. The default is *not* to write the oFFs chunk; it only writes one if one or both offs...

The oFFs chunk is not part of the PNG specification. Instead, it is specified in the PNG extensions document, which says, "Although oFFs can specify an image placement that is partially or wholly outside the page boundaries, the result of such placement is application-dependent." Yes of c...

To glennrp: clearly, it is a bug if imagemagick produces PNG images with strange offsets that gimp (and other utilities) cannot handle.
There is no motivation for these strange offsets.

Thanks for the reply. (I made the same two remarks on the page linked to.) This was not a help request. Two old bugs were reported in the hope that some developer who knows this code actually fixes the problem, instead of posting a workaround. I would have sent it to a bugzilla, but perhaps there is...

The ImageMagick utility import can be used to make screenshots of part of the screen. Problem 1: Very often this fails and produces a garbage picture, with black rectangles obscuring parts of the content. Problem 2: When a PNG picture is successfully made, it does not satisfy the PNG standard, and g...