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2014/10/15 ¤U¤È 10:13:08

iphone Programming Glossary: rawdata

Retrieving a pixel alpha value for a UIImage

http://stackoverflow.com/questions/1042830/retrieving-a-pixel-alpha-value-for-a-uiimage

NSUInteger height CGImageGetHeight image CGColorSpaceRef colorSpace CGColorSpaceCreateDeviceRGB rawData malloc height width 4 bytesPerPixel 4 bytesPerRow bytesPerPixel width NSUInteger bitsPerComponent 8.. bytesPerPixel width NSUInteger bitsPerComponent 8 CGContextRef context CGBitmapContextCreate rawData width height bitsPerComponent bytesPerRow colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big.. int byteIndex bytesPerRow uiViewPoint.y uiViewPoint.x bytesPerPixel unsigned char alpha rawData byteIndex 3 However I don't get the values I expect. For a completely black transparent area of the..

Convert image to grayscale

http://stackoverflow.com/questions/1298867/convert-image-to-grayscale

bytesPerPixel width CGColorSpaceRef colorSpace CGColorSpaceCreateDeviceRGB unsigned char rawData malloc height width 4 CGContextRef context CGBitmapContextCreate rawData width height bitsPerComponent.. unsigned char rawData malloc height width 4 CGContextRef context CGBitmapContextCreate rawData width height bitsPerComponent bytesPerRow colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big.. CGContextDrawImage context CGRectMake 0 0 width height image CGContextRelease context return rawData UIImage processImage UIImage pImage DebugLog @ processing image unsigned char rawData self getBytesForImage..

Retrieving a pixel alpha value for a UIImage

http://stackoverflow.com/questions/1042830/retrieving-a-pixel-alpha-value-for-a-uiimage

image uiImage.CGImage NSUInteger width CGImageGetWidth image NSUInteger height CGImageGetHeight image CGColorSpaceRef colorSpace CGColorSpaceCreateDeviceRGB rawData malloc height width 4 bytesPerPixel 4 bytesPerRow bytesPerPixel width NSUInteger bitsPerComponent 8 CGContextRef context CGBitmapContextCreate rawData width height.. rawData malloc height width 4 bytesPerPixel 4 bytesPerRow bytesPerPixel width NSUInteger bitsPerComponent 8 CGContextRef context CGBitmapContextCreate rawData width height bitsPerComponent bytesPerRow colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big CGColorSpaceRelease colorSpace CGContextDrawImage context.. the given alpha channel using the coordinates from the UIImageView. int byteIndex bytesPerRow uiViewPoint.y uiViewPoint.x bytesPerPixel unsigned char alpha rawData byteIndex 3 However I don't get the values I expect. For a completely black transparent area of the image I get non zero values for the alpha channel. Do I need..

Convert image to grayscale

http://stackoverflow.com/questions/1298867/convert-image-to-grayscale

image NSUInteger height CGImageGetHeight image NSUInteger bytesPerRow bytesPerPixel width CGColorSpaceRef colorSpace CGColorSpaceCreateDeviceRGB unsigned char rawData malloc height width 4 CGContextRef context CGBitmapContextCreate rawData width height bitsPerComponent bytesPerRow colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big.. width CGColorSpaceRef colorSpace CGColorSpaceCreateDeviceRGB unsigned char rawData malloc height width 4 CGContextRef context CGBitmapContextCreate rawData width height bitsPerComponent bytesPerRow colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big CGColorSpaceRelease colorSpace CGContextDrawImage context.. kCGBitmapByteOrder32Big CGColorSpaceRelease colorSpace CGContextDrawImage context CGRectMake 0 0 width height image CGContextRelease context return rawData UIImage processImage UIImage pImage DebugLog @ processing image unsigned char rawData self getBytesForImage pImage NSUInteger width pImage.size.width NSUInteger..

Retrieving a pixel alpha value for a UIImage

http://stackoverflow.com/questions/1042830/retrieving-a-pixel-alpha-value-for-a-uiimage

CGImageGetWidth image NSUInteger height CGImageGetHeight image CGColorSpaceRef colorSpace CGColorSpaceCreateDeviceRGB rawData malloc height width 4 bytesPerPixel 4 bytesPerRow bytesPerPixel width NSUInteger bitsPerComponent 8 CGContextRef context.. 4 bytesPerRow bytesPerPixel width NSUInteger bitsPerComponent 8 CGContextRef context CGBitmapContextCreate rawData width height bitsPerComponent bytesPerRow colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big CGColorSpaceRelease.. from the UIImageView. int byteIndex bytesPerRow uiViewPoint.y uiViewPoint.x bytesPerPixel unsigned char alpha rawData byteIndex 3 However I don't get the values I expect. For a completely black transparent area of the image I get non zero..

Convert image to grayscale

http://stackoverflow.com/questions/1298867/convert-image-to-grayscale

image NSUInteger bytesPerRow bytesPerPixel width CGColorSpaceRef colorSpace CGColorSpaceCreateDeviceRGB unsigned char rawData malloc height width 4 CGContextRef context CGBitmapContextCreate rawData width height bitsPerComponent bytesPerRow colorSpace.. CGColorSpaceCreateDeviceRGB unsigned char rawData malloc height width 4 CGContextRef context CGBitmapContextCreate rawData width height bitsPerComponent bytesPerRow colorSpace kCGImageAlphaPremultipliedLast kCGBitmapByteOrder32Big CGColorSpaceRelease.. colorSpace CGContextDrawImage context CGRectMake 0 0 width height image CGContextRelease context return rawData UIImage processImage UIImage pImage DebugLog @ processing image unsigned char rawData self getBytesForImage pImage NSUInteger..

Creating UIImage from raw RGBA data

http://stackoverflow.com/questions/4545237/creating-uiimage-from-raw-rgba-data

My code looks like as follows height and width are integers denoting the dimensions of the image unsigned char rawData malloc width height 4 for int i 0 i width height i rawData 4 i red_val rawData 4 i 1 green_val rawData 4 i 2 blue_val rawData.. integers denoting the dimensions of the image unsigned char rawData malloc width height 4 for int i 0 i width height i rawData 4 i red_val rawData 4 i 1 green_val rawData 4 i 2 blue_val rawData 4 i 3 255 I Have the correct values displayed ensuring.. dimensions of the image unsigned char rawData malloc width height 4 for int i 0 i width height i rawData 4 i red_val rawData 4 i 1 green_val rawData 4 i 2 blue_val rawData 4 i 3 255 I Have the correct values displayed ensuring the rawData is well..