I want to use the function CGImageSourceCreateThumbnailAtIndex to create a thumbnail from an UIImage. All I have is the UIImage itself. The image is the snapshot on a UIView. Please, I don't want ...

I have built a camera using AVFoundation. Once my AVCaptureStillImageOutput has completed its captureStillImageAsynchronouslyFromConnection:completionHandler: method, I create a NSData object lik...

I got this following code that access a PHAsset. I need to pass a CGImage out of this: let imageManager = PHImageManager.defaultManager() imageManager.requestImageDataForAsset(self.asset!, options...

I'm using the XZINGObjC framework to create an EAN-Barcode-Image. Following the documentation, I'm doing it like //in viewDidAppear //XZING: create Matrix NSString* eanString = @"1234567890123...

Updated to Xcode 7 and getting this (warning?) message while an image was being rendered in an operation: CreateWrappedSurface() failed for a dataprovider-backed CGImageRef. There was no messa...

I have original image and I can cycle all pixels using @patrick-rutkowski answer here. Also I have this answer seems to create image with pixel data. But I can't understand how to combine these two...

I'm trying to read pixels out of the screen buffer, I'm creating a CGImageRef with CGDisplayCreateImage, but the values for CGImageGetWidth and CGImageGetBytesPerRow Don't make sense together, divi...

while working with OpenCV I need to convert a NSImage to an OpenCV multi-channel 2D matrix (cvMat) and vice versa. What's the best way to do it? Greets, Dom

I'm generating a bunch of tiles for CATiledLayer. It takes about 11 seconds to generate 120 tiles at 256 x 256 with 4 levels of detail on an iPhone 4S. The image itself fits within 2048 x 2048. My...

I'm building an Iphone app that needs to convert a UIImage to a CGImageRef. I have no idea how to do this and would love some help. I have no background in working with images... :)

I am writing this method to calculate the average R,G,B values of an image. The following method takes a UIImage as an input and returns an array containing the R,G,B values of the input image. I h...

i converted NSData of image to CGImage as below but i am getting memory leaks there but any one tell me how to convert that with out getting leaks: CFDataRef imgData; CGDataProviderRef imgDataProv...

I am trying process an image in CoreGraphics and then return the processed image back to an NSImage for saving and displaying. I have ample resources on how to perform these functions in iOS but th...

The following code compiles fine with manual memory management, but fails under ARC: CALayer *layer = [CALayer layer]; layer.contents = [[UIImage imageNamed:@"dial.png"] CGImage]; The error is: ...

First, check out this very handy extension to CALayer from elsewhere on SO. It helps you determine if a point in a layer's contents-assigned CGImageRef is or isn't transparent. n.b.: There is no g...

I am trying to resize a 10x10 pixel CGImageRef, captured like this: CGImageRef imageRef = CGImageCreateWithImageInRect(screenShot, CGRectMake(mouseLoc.x-5, screen_height-mouseLoc.y-5, 10, 10)); C...