unsupported parameter combination 解决办法

colorSpace = CGColorSpaceCreateDeviceRGB();

//    CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst;

//    CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst;

    //error

    CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Little | kCGImageAlphaNone;

http://lists.apple.com/archives/carbon-dev/2007/Jun/msg00014.html

CGBitmapContextCreate: unsupported parameter combination: set CGBITMAP_CONTEXT_LOG_ERRORS environmental variable to see the details

I am trying to use CGBitmapContextCreate to create a context for a raw image, but I get this error message:

CGBitmapContextCreate: unsupported parameter combination: 8 integer bits/component; 32 bits/pixel; 3-component colorspace; kCGImageAlphaFirst.

Here is how I create my color space

...

FContext := CGBitmapContextCreate(FBits, NewWidth, NewHeight, 8, Stride, FColorSpace, kCGImageAlphaFirst or kCGBitmapByteOrder32Little);

...

Any ideas about what is wrong? i looked at CGBitmapContextCreate's docs here, but they say that it supports 32-bits images with 8 bits per channel:

http://developer.apple.com/documentation/GraphicsImaging/Reference/ CGImage/Reference/reference.html#//apple_ref/doc/c_ref/CGBitmapInfo

That just lists possible values for CGBitmapInfo. You should check out <http://developer.apple.com/qa/qa2001/qa1037.html>. It lists the only legal combinations of bitsPerComponent, colorspace and bitmapInfo that CGBitmapContextCreate supports. It is a fairly limited set and any other combinations cause CGBitmapContextCreate to fail.

steve

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• Re: Unsupported format for CGBitmapContextCreate

• From: "Felipe Monteiro de Carvalho" <email@hidden>