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2014/10/15 ¤U¤È 10:04:35

iphone Programming Glossary: bitmapdata

How to get the RGB values for a pixel on an image on the iphone

http://stackoverflow.com/questions/144250/how-to-get-the-rgb-values-for-a-pixel-on-an-image-on-the-iphone

and declared with corresponding synthesized properties Reference to Quartz CGImage for receiver self CFDataRef bitmapData Buffer holding raw pixel data copied from Quartz CGImage held in receiver self UInt8 pixelByteData A pointer to the first.. a buffer to store bitmap data unitialized memory as long as the data self setPixelBitData malloc CFDataGetLength bitmapData Copy image data into allocated buffer CFDataGetBytes bitmapData CFRangeMake 0 CFDataGetLength bitmapData pixelByteData Cast.. the data self setPixelBitData malloc CFDataGetLength bitmapData Copy image data into allocated buffer CFDataGetBytes bitmapData CFRangeMake 0 CFDataGetLength bitmapData pixelByteData Cast a pointer to the first element of pixelByteData Essentially..

Getting pixel data from UIImageView — works on simulator, not device

http://stackoverflow.com/questions/1911360/getting-pixel-data-from-uiimageview-works-on-simulator-not-device

NSUInteger floor point.y if x width y height CGDataProviderRef provider CGImageGetDataProvider cgImage CFDataRef bitmapData CGDataProviderCopyData provider const UInt8 data CFDataGetBytePtr bitmapData size_t offset width y x 4 UInt8 red data offset.. CGImageGetDataProvider cgImage CFDataRef bitmapData CGDataProviderCopyData provider const UInt8 data CFDataGetBytePtr bitmapData size_t offset width y x 4 UInt8 red data offset UInt8 blue data offset 1 UInt8 green data offset 2 UInt8 alpha data offset.. y x 4 UInt8 red data offset UInt8 blue data offset 1 UInt8 green data offset 2 UInt8 alpha data offset 3 CFRelease bitmapData color UIColor colorWithRed red 255.0f green green 255.0f blue blue 255.0f alpha alpha 255.0f return color iphone uiimageview..

Image processing Glamour filter in iphone

http://stackoverflow.com/questions/3549396/image-processing-glamour-filter-in-iphone

UIImage image CGImageRef cgImage image CGImage CGDataProviderRef provider CGImageGetDataProvider cgImage CFDataRef bitmapData CGDataProviderCopyData provider UInt8 data UInt8 CFDataGetBytePtr bitmapData int width image.size.width int height image.size.height.. CGImageGetDataProvider cgImage CFDataRef bitmapData CGDataProviderCopyData provider UInt8 data UInt8 CFDataGetBytePtr bitmapData int width image.size.width int height image.size.height NSInteger myDataLength width height 4 for int i 0 i myDataLength.. colorSpaceRef YOU CAN RELEASE THIS NOW CGDataProviderRelease provider2 YOU CAN RELEASE THIS NOW CFRelease bitmapData UIImage sepiaImage UIImage imageWithCGImage imageRef CGImageRelease imageRef YOU CAN RELEASE THIS NOW return sepiaImage..

How to render to offscreen bitmap then blit to screen using Core Graphics

http://stackoverflow.com/questions/410313/how-to-render-to-offscreen-bitmap-then-blit-to-screen-using-core-graphics

graphics bitblit share improve this question To render into an offscreen context and save it as a CGImageRef void bitmapData calloc height bytesPerLine CGContextRef offscreen CGBitmapContextCreate ... bitmapData ... draw stuff into offscreen CGImageRef.. save it as a CGImageRef void bitmapData calloc height bytesPerLine CGContextRef offscreen CGBitmapContextCreate ... bitmapData ... draw stuff into offscreen CGImageRef image CGBitmapContextCreateImage offscreen CFRelease offscreen free bitmapData.. ... draw stuff into offscreen CGImageRef image CGBitmapContextCreateImage offscreen CFRelease offscreen free bitmapData To draw it on the screen void drawRect CGRect rect CGContextRef context UIGraphicsGetCurrentContext CGContextDrawImage context..

How to draw a color wheel in objective-c

http://stackoverflow.com/questions/5108921/how-to-draw-a-color-wheel-in-objective-c

touches at a given coordinate . void drawRect CGRect rect int dim self.bounds.size.width should always be square. bitmapData CFDataCreateMutable NULL 0 CFDataSetLength bitmapData dim dim 4 generateColorWheelBitmap CFDataGetMutableBytePtr bitmapData.. rect int dim self.bounds.size.width should always be square. bitmapData CFDataCreateMutable NULL 0 CFDataSetLength bitmapData dim dim 4 generateColorWheelBitmap CFDataGetMutableBytePtr bitmapData dim luminance UIImage image createUIImageWithRGBAData.. CFDataCreateMutable NULL 0 CFDataSetLength bitmapData dim dim 4 generateColorWheelBitmap CFDataGetMutableBytePtr bitmapData dim luminance UIImage image createUIImageWithRGBAData bitmapData self.bounds.size.width self.bounds.size.height CFRelease..

Filling a portion of an image with color

http://stackoverflow.com/questions/8124308/filling-a-portion-of-an-image-with-color

colorspace CGColorSpaceCreateDeviceRGB float areaFloat area.size.width 4 area.size.height unsigned char bitmapData malloc areaFloat CGContextRef context CGBitmapContextCreate bitmapData area.size.width area.size.height 8 4.. 4 area.size.height unsigned char bitmapData malloc areaFloat CGContextRef context CGBitmapContextCreate bitmapData area.size.width area.size.height 8 4 area.size.width colorspace kCGImageAlphaPremultipliedLast CGContextTranslateCTM.. Seek through all pixels. float transparentPixels 0 for int i 0 i int areaFloat i 4 Count each transparent pixel. if bitmapData i 3 1.0 255.0 0 transparentPixels 1 free bitmapData Calculate the percentage of transparent pixels. float hitTolerance..