On Thu, Dec 16, 2010 at 7:48 PM, Gideon King <gid...@novamind.com> wrote:
> Hi, I have an arbitrary (user supplied) image, and I want to get the RGBA > values of each pixel of the image. I'm thinking that I should create it as > an NSImage and then use the TIFFRepresentation to get it into an > NSBitmapImageRep object, and then walk through and pick up the colors, but > it appears that the NSBitmapImageRep could be in a wide variety of internal > formats. > > Is there either some generic way of finding the RGBA values, or ensuring > that the NSBitmapImageRep is created in a fixed color space that I can code > for? ...or some other way of solving this problem? > Yes. Create an NSBitmapImageRep in a fixed pixel format and draw the NSImage in it. Now you have bits in a canonical pixel format. The TIFFRepresentation thing is a not very good hack that unfortunately seems to have critical mass in the community - that code just won't die. TIFFRepresentation is good method to call if you're sending data outside of your process, say to the pasteboard or to disk. It's pretty much always wrong if the data isn't going to leave your address space. See the section "NSBitmapImageRep: CoreGraphics impedance matching and performance notes" in the AppKit release notes<http://developer.apple.com/library/mac/#releasenotes/Cocoa/AppKit.html>for more detail. -Ken Cocoa Frameworks > > Thanks > > Gideon > > > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/cocoa-dev/kenferry%40gmail.com > > This email sent to kenfe...@gmail.com > _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
