The old trick that involved using the private API CGSAddWindowFilter() seems to no longer work in Mavericks for some reason. I tried some code described in How does on-screen color inversion work i...

I'm trying to apply CoreImage filter on my fullscreen rendering output but looks like I'm missing something because I'm getting black screen as output. First I draw whole scene to a texture. Then...

I'm using Core Image filters in my app, everything works fine on my iPhone 5 device running iOS 7, but when I test it on iPhone 4s, which has only a total memory of 512MB, the app crashes. Here's...

So, I have an app that uses the face detection feature of Core Image ( https://itunes.apple.com/us/app/ace-freakyface-cartoon-mask/id454513332?mt=8 ) and I just got the new iPhone 5s and the app no...

I'm using CISourceOverCompositing to blend two images. It works ok with same size images with this code: CIFIlter *filter1 = [CIFilter filterWithName: @"CISourceOverCompositing"]; [filter1 setDefa...

I am trying to use the iOS 7 style glass effect in my glass by applying image effects to a screenshot of a MKMapView. This UIImage category, provided by Apple, is what I am using as a baseline. Thi...

I'm trying out SpriteKit with the following setup: An SKScene with two child nodes used merely for grouping other nodes: foreground and background. background is really empty as of now, but would...

I want to apply filters (effects) on a video file while the video is playing. I'm currently using @BradLarson 's (great) GPUImage framework to do so, the problem here is that the framework doesn'...

I'm using GPUImage framework of Brad Larson in my app and I need to make a mask of mask.jpg and photo. So mask images are two colors images with black background and white geometric figure. So basi...

I'm creating a CIImage from a UIImage as follows: CIImage* someCIImage = [CIImage imageWithCGImage:someUIImage.CGImage]; Comparing someCIImage.extent.size.width/height with someUIImage.size.wid...

When creating a Core Image CIContext using the following: contextWithCGLContext:pixelFormat:colorSpace:options: You can specify a color space with a CGColorSpaceRef. However, the options diction...

I am having a strange problem in my project. What I want to do is that, a user will paint or draw using swipe over a image as overlay and I just need to crop the area from the image that is below t...

My UIView is using an instance of TBPaperLayer for its layer. +(Class)layerClass { return [TBPaperLayer class]; } I would like to create a CIFilter to modify the appearance of this layer - espe...

Let's say I have an Image that's 100x100. I want to place the image onto a larger canvas size that's 500x500. My current approach is to use UIGraphics to create a Context, then draw the image ont...

I am trying to change the white point/white balance programmatically. This is what I want to accomplish: - Choose a (random) pixel from the image - Get color of that pixel - Transform the image so ...

I try something to create an UIImage with a frame and color but don't know what the correct way. UIImage *aImage = [UIImage imageWithCIImage:[CIImage imageWithColor:[CIColor colorWithCGColor:[UIC...

Does someone know how to render a CIImage directly into an OpenGL ES 2.0 texture via drawImage:inRect:fromRect: from an EAGL CIContext on iOS? Rendering via a normal CIContext via createCGImage:fro...

I am using CIFilter and the CIHueBlendMode in order to blend an image (foreground) and a red layer (background) I am doing the exact same thing in Photoshop CS6 with the Hue Blend Mode (copied the...

I'm trying to use CATransition's filter property with the new iOS 6 transition animations (CIBarsSwipeTransition, CICopyMachineTransition, etc.). The CIFilter documentation says that these are avai...

I need to make an application in iphone which needs to calculate noise, geometric deformation other distortions in an image. How to do this? I have done some image processing stuff with opencv + ip...

I've been trying a ton of different options and tricks for getting a UIImage to build properly from a CIImage. But, every time I create the CIImage its colors seem to be inverted. The most recent ...

I have 2 UIImageViews that are shown on top of each other. One of them can be dragged around using a Gesture Recognizer. Is there a way that the ImageViews can be rendered using a blend mode like...

I am trying to run some core image filters in the most efficient way possible. Trying to avoid memory warnings and crashes, which I am getting when rendering large images. I am looking at Apple's C...

I'm mapping several photoshop elements to CIFilter, the only one I'm having trouble with is this Levels Adjustment: Which CI Filter (or combination of filters) would let me utilize the 16, 1.7...

When I setup a GLKViewController/GLKView for drawing with CoreImage I sometimes get the notice in the title. The setup looks like this: _context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingA...