cgimage

I have a screenshot of the entire screen, screenshot , generated using the following: let layer = UIApplication.sharedApplication().keyWindow!.layer let scale = UIScreen.mainScreen().scale UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale); layer.renderInContext(UIGraphicsGetCurrentContext()) let screenshot = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() I'd like to crop it so that the tab bar is not included, and I tried using the following code: let crop = CGRectMake(0, 0, //"start" at the upper-left corner self.view.bounds.width, //include half

I have a UIImage which is loaded from a CIImage with: tempImage = [UIImage imageWithCIImage:ciImage]; The problem is I need to crop tempImage to a specific CGRect and the only way I know how to do this is by using CGImage . The problem is that in the iOS 6.0 documentation I found this: CGImage If the UIImage object was initialized using a CIImage object, the value of the property is NULL. A. How to convert from CIImage to CGImage? I'm using this code but I have a memory leak (and can't understand where): +(UIImage*)UIImageFromCIImage:(CIImage*)ciImage { CGSize size = ciImage.extent.size;

I'm using the following code to crop and create a new UIImage out of a bigger one. I've isolated the issue to be with the function CGImageCreateWithImageInRect() which seem to not set some CGImage property the way I want. :-) The problem is that a call to function UIImagePNGRepresentation() fails returning a nil. CGImageRef origRef = [stillView.image CGImage]; CGImageRef cgCrop = CGImageCreateWithImageInRect( origRef, theRect); UIImage *imgCrop = [UIImage imageWithCGImage:cgCrop]; ... NSData *data = UIImagePNGRepresentation ( imgCrop); -- libpng error: No IDATs written into file Any idea what

Problem: Cropping with the image zoomed out is fine. Cropping with the image zoomed in is showing the image above what is should be. The yOffset I have in there is because the crop square I want starts below where the scrollview does. Code: CGRect rect; float yOffset = 84; rect.origin.x = floorf([scrollView contentOffset].x * zoomScale); rect.origin.y = floorf(([scrollView contentOffset].y + yOffset) * zoomScale); rect.size.width = floorf([scrollView bounds].size.width * zoomScale); rect.size.height = floorf((320 * zoomScale)); if (rect.size.width > 320) { rect.size.width = 320; } if (rect

I have a rather large, almost full screen image that I'm going to be displaying on an iPad. The image is about 80% transparent. I need to, on the client, determine the bounding box of the opaque pixels, and then crop to that bounding box. Scanning other questions here on StackOverflow and reading some of the CoreGraphics docs, I think I could accomplish this by: CGBitmapContextCreate(...) // Use this to render the image to a byte array .. - iterate through this byte array to find the bounding box .. CGImageCreateWithImageInRect(image, boundingRect); That just seems very inefficient and clunky.

I try to get the screenshot from all monitors connected with my MAC to one picture. I know, how I can do this if every monitor's screenshot will saved to different pictures, but it is not what I want. I found function CGGetDisplaysWithRect , but my solution don't work, because output picture is empty. I expect, that problem with function CGDisplayCreateImageForRect (*displays, rect), because first parameter must be CGDirectDisplayID type, but not CGDirectDisplayID*. But I can't find function, which can create one picture with some CGDirectDisplayID objects. Help me please!!! #include <stdio.h>