Article View: comp.sys.next.programmer
Article #18Device independent cached images?
From: Daniel Filiberti
Date: Tue, 27 Oct 1992 21:25
Date: Tue, 27 Oct 1992 21:25
49 lines
2601 bytes
2601 bytes
Hi Everybody! I'm having problems doing the following... 1) I load a 24-bit TIFF image into an NXImage with the initFromFile: method. I assume that this method automagically creates an NXBitmapImageRep for you and adds it to the images representation list. 2) A region is traced in the image via the user interface and stored as a postscript user path. 3) I now want to "etch" out the region traced by the user from the image and get at the data. So, I create another NXImage, lockFocus on it, and use some postscript magic to set the clipping path and copy from the original image into the new one. This new image is created with the initSize: method, and so I assume that it creates a NXCachedImageRep to hold the image. 4) Finally, I need to get at the bitmap data in the etched image. One way to do this is to use the NXReadBitmap() function to read the image into a chunk of memory. Now, when I do this on our NeXTDimension system, everything works fine. But, if I'm running the application on a monochrome slab, NXSizeBitmap() and NXReadBitmap() always treat the image as 2 bps, and 4 spp (RGBA)! Furthermore, even if I try to save out the etched image with writeTIFF:, it gets saved as a monochrome TIFF! So, how do I manage to get at the color bitmap data in this situation? I've tried everything that I can imagine to do this, and nothing seems to work. The debugger shows the cached image rep as being 8 bps and 3 color...so its obviously stored as color, why does it always get converted to monochrome? Any help greatly appreciated! Daniel --- ************************************************************ Motto for a monitor, "It's better to burn out, than to fade away..." [8?)} ************************************************************ Daniel Filiberti Oregon Health Sciences University Biomedical Information Communication Center (BICC) 3181 Sam Jackson Park Road Portland, Oregon 97201-3098 email: filibert@ohsu.edu
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<1992Oct27.212529.12565@ohsu.edu>Path:
arc1-ca.pugleaf.net!sparky!uunet!charon.amdahl.com!pacbell.com!ames!decwrl!usenet.coe.montana.edu!news.u.washington.edu!ogicse!pdxgate!steele!newsShow Full Headers
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Path: arc1-ca.pugleaf.net!sparky!uunet!charon.amdahl.com!pacbell.com!ames!decwrl!usenet.coe.montana.edu!news.u.washington.edu!ogicse!pdxgate!steele!news From: filibert@vista (Daniel Filiberti) Newsgroups: comp.sys.next.programmer Subject: Device independent cached images? Keywords: image, color, NXImage, bitmap Message-ID: <1992Oct27.212529.12565@ohsu.edu> Date: 27 Oct 92 21:25:29 GMT Article-I.D.: ohsu.1992Oct27.212529.12565 Sender: news@ohsu.edu Reply-To: filibert@ohsu.edu Organization: Oregon Health Sciences University Lines: 49 Nntp-Posting-Host: vista