Re: ExportImagePixelArea
Bob Friesenhahn <[email protected]>
| Newsgroups | gmane.comp.video.graphicsmagick.help |
|---|---|
| Message-ID | <[email protected]> |
On Tue, 5 Jun 2018, Adam Morissun wrote: > Hi. Would someone explain how to use ExportImagePixelArea() ? I cannot make > it work for the life of me. > > I've attached the smallest C code I could devise to demonstrate my problem. > I'm using Gimp to examine the '/tmp/pixels_**.data' files. You are definitely closing in on the solution. The GetImagePixels() requests that you currently have commented out are vitally important. Even if you have no intention to use the returned pointer, these requests are also setting the pixel region/area that ExportImagePixelArea() will then use. Later on in the implementation (in ExportViewPixelArea()), the AccessCacheViewPixels() function returns the same pointer that GetImagePixels() previously returned, and AcquireCacheViewIndexes() returns the colormap indexes if the image is colormapped (image->storage_class == PseudoClass). Bob ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot