图片数据类型转换 NSImage、CIImage、CGImageRef

#import <QuartzCore/CIFilter.h>

// convert NSImage to bitmap

NSImage * myImage  = [self currentImage];

NSData  * tiffData = [myImage TIFFRepresentation];

NSBitmapImageRep * bitmap;

bitmap = [NSBitmapImageRep imageRepWithData:tiffData];

// create CIImage from bitmap

CIImage * ciImage = [[CIImage alloc] initWithBitmapImageRep:bitmap];

// create affine transform to flip CIImage

NSAffineTransform *affineTransform = [NSAffineTransform transform];

[affineTransform translateXBy:0 yBy:128];

[affineTransform scaleXBy:1 yBy:-1];

// create CIFilter with embedded affine transform

CIFilter *transform = [CIFilter filterWithName:@"CIAffineTransform"];

[transform setValue:ciImage forKey:@"inputImage"];

[transform setValue:affineTransform forKey:@"inputTransform"];

// get the new CIImage, flipped and ready to serve

CIImage * result = [transform valueForKey:@"outputImage"];

// draw to view

[result drawAtPoint: NSMakePoint ( 0,0 )

fromRect: NSMakeRect  ( 0,0,128,128 )

operation: NSCompositeSourceOver

fraction: 1.0];

// cleanup

[ciImage release];

- (NSImage*) imageFromCGImageRef:(CGImageRef)image

{

NSRect imageRect = NSMakeRect(0.0, 0.0, 0.0, 0.0);

CGContextRef imageContext = nil;

NSImage* newImage = nil;

// Get the image dimensions.

imageRect.size.height = CGImageGetHeight(image);

imageRect.size.width = CGImageGetWidth(image);

// Create a new image to receive the Quartz image data.

newImage = [[[NSImage alloc] initWithSize:imageRect.size] autorelease];

[newImage lockFocus];

// Get the Quartz context and draw.

imageContext = (CGContextRef)[[NSGraphicsContext currentContext] graphicsPort];

CGContextDrawImage(imageContext, *(CGRect*)&imageRect, image);

[newImage unlockFocus];

return newImage;

}

- (CGImageRef)nsImageToCGImageRef:(NSImage*)image;

{

NSData * imageData = [image TIFFRepresentation];

CGImageRef imageRef;

if(imageData)

{

CGImageSourceRef imageSource =

CGImageSourceCreateWithData(

(CFDataRef)imageData,  NULL);

imageRef = CGImageSourceCreateImageAtIndex(

imageSource, 0, NULL);

}

return imageRef;

}