[Amorya]

OK, in the app I'm writing I'm passed some PNG data and need to return it as RGBA.

What I've been doing is this:

Code:
	NSBitmapImageRep *rep = [[NSBitmapImageRep imageRepWithData:[NSData dataWithBytes:data length:len]] retain];
	*width = [rep pixelsWide];
	*height = [rep pixelsHigh];
//	NSLog(@"%i %i %i", *width, *height, [rep bitsPerPixel]/8);
	unsigned char *pixels = malloc(*width * *height * [rep bitsPerPixel]/8);
	memcpy(pixels, [rep bitmapData], (*width * *height * [rep bitsPerPixel]/8));
	return pixels;

(data contains the PNG and len contains the length).

The problem is, not all these PNGs are 32-bit, and not all contain alpha. I need the bitmap data I return to be in the same format every time... preferably 32-bit RGBA.

Any ideas how I can do this?


Amorya

[Dair Grant]

Create a QuickTime graphics importer for your image, then get a CGImageRef with GraphicsImportCreateCGImage.

Allocate a width * height * sizeof(UInt32) block of memory to hold your 32-bpp RGBA data, then use CGBitmapContextCreate to create a CGContextRef that uses that memory.

Draw your image into the context with CGContextDrawImage, and QT will expand the image data out to the depth of the context.

[Amorya]

Cool, thanks. Guess I'm off to read up on Quicktime!