is there any Possibility to create a image out of a UIView?
Thanks,
Andreas
#import "QuartzCore/QuartzCore.h" after you added the framework to your project. Then do:
UIGraphicsBeginImageContext(yourView.frame.size);
[[yourView layer] renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// The result is *screenshot
I have used the answer to improve it even further. Unfortunately, the original code only produced a mirrored image.
So here's the working code:
- (UIImage *) imageFromView:(UIView *)view {
UIGraphicsBeginImageContext(view.frame.size);
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(currentContext, 0, view.size.height);
// passing negative values to flip the image
CGContextScaleCTM(currentContext, 1.0, -1.0);
[[appDelegate.scatterPlotView layer] renderInContext:currentContext];
UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return screenshot;
}
Related
I want to convert UIView to UIImage, in which the view is in background and when I checked view hierarchy, it is there as white space, probably it wont get loaded..
What I wanted to do is load the view into memory and convert into image.
you just need to initialize your view with your required frame and then pass to below code as targetView. Initialize your view before you call screen capture method like below
UIView *targetView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 568)]; //Initilization
UIImage *capturedImage = [self captureScreen:targetView]; //Call method
- (UIImage *)captureScreen:(UIView*)targetView
{
UIView* captureView = targetView;
UIGraphicsBeginImageContextWithOptions(captureView.bounds.size, captureView.opaque, 0.0);
[captureView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * screenshot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGRect cropRect = CGRectMake(0 ,0 ,captureView.frame.size.width ,captureView.frame.size.height);
UIGraphicsBeginImageContextWithOptions(cropRect.size, captureView.opaque, 1.2f);
[screenshot drawInRect:cropRect];
UIImage * customScreenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return customScreenShot;
}
Use this:
- (UIImage*)snapShot:(UIView*)myView {
UIGraphicsBeginImageContext(myView.frame.size);
[myView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return viewImage;
}
In objective-c, I make a circle shape programmatically by following codes:
+(UIImage *)makeRoundedImage:(CGSize) size backgroundColor:(UIColor *) backgroundColor cornerRadius:(int) cornerRadius
{
UIImage* bgImage = [self imageWithColor:backgroundColor andSize:size];;
CALayer *imageLayer = [CALayer layer];
imageLayer.frame = CGRectMake(0, 0, size.width, size.height);
imageLayer.contents = (id) bgImage.CGImage;
imageLayer.masksToBounds = YES;
imageLayer.cornerRadius = cornerRadius;
UIGraphicsBeginImageContext(bgImage.size);
[imageLayer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *roundedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return roundedImage;
}
The imageWithColor method is as following:
+(UIImage *)imageWithColor:(UIColor *)color andSize:(CGSize)size
{
//quick fix, or pop up CG invalid context 0x0 bug
if(size.width == 0) size.width = 1;
if(size.height == 0) size.height = 1;
//---quick fix
UIImage *img = nil;
CGRect rect = CGRectMake(0, 0, size.width, size.height);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context,
color.CGColor);
CGContextFillRect(context, rect);
img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
Then I used it to create a pure color circle shape image, but what I found is the circle image is not perfect rounded. As an example, please see following code:
CGSize size = CGSizeMake(diameter, diameter);
int r = ceil((float)diameter/2.0);
UIImage *imageNormal = [self makeRoundedImage:size backgroundColor:backgroundColor cornerRadius:r];
[slider setThumbImage:imageNormal forState:UIControlStateNormal];
First I created a circle image, then I set the image as the thumb to a UISlider. But what shown is as the picture shown below:
You can see the circle is not an exact circle. I'm thinking probably it caused by the screen resolution issue? Because if I use an image resource for the thumb, I need add #2x. Anybody know the reason? Thanx in advance.
updated on 8th Aug 2015.
Further to this question and the answer from #Noah Witherspoon, I found the blurry edge issue has been solved. But still, the circle looks like being cut. I used the code as following:
CGRect rect = CGRectMake(0.0f, 0.0f, radius*2.0f, radius*2.0f);
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0.0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, color.CGColor);
CGContextFillEllipseInRect(context, rect);
UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
And the circle looks like:
You can see the edge has been cut.
I changed the code as following:
CGRect rect = CGRectMake(0.0f, 0.0f, radius*2.0f+4, radius*2.0f+4);
CGRect rectmin = CGRectMake(2.0f, 2.0f, radius*2, radius*2);
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0.0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, color.CGColor);
CGContextFillEllipseInRect(context, rectmin);
UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
You can see the circle looks better(The top edge and the bottom edge):
I made the fill rect size smaller, and the edge looks better, but I don't think it's a nice solution. Still, does anybody know why this happen?
From your screenshot it looks like you do actually have a circular image, but its scale is wrong—it’s not Retina—so it looks blurry and not-circular. The key thing is that instead of using UIGraphicsBeginImageContext which defaults to a scale of 1.0 (as compared to your screen, which is at a scale of 2.0 or 3.0), you should be using UIGraphicsBeginImageContextWithOptions. Also, you don’t need to make a layer or a view to draw a circle in an image context.
+ (UIImage *)makeCircleImageWithDiameter:(CGFloat)diameter color:(UIColor *)color {
UIGraphicsBeginImageContextWithOptions(CGSizeMake(diameter, diameter), NO, 0 /* scale (0 means “use the current screen’s scale”) */);
[color setFill];
CGContextFillEllipseInRect(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, diameter, diameter));
UIImage *image = UIGraphicsGetImageFromCurrentContext();
UIGraphicsEndImageContext();
return image;
}
If you want to get a circle every time try this:
- (UIImage *)makeCircularImage:(CGSize)size backgroundColor:(UIColor *)backgroundColor {
CGSize squareSize = CGSizeMake((size.width > size.height) ? size.width : size.height,
(size.width > size.height) ? size.width : size.height);
UIView *circleView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, squareSize.width, squareSize.height)];
circleView.layer.cornerRadius = circleView.frame.size.height * 0.5f;
circleView.backgroundColor = backgroundColor;
circleView.opaque = NO;
UIGraphicsBeginImageContextWithOptions(circleView.bounds.size, circleView.opaque, 0.0);
[circleView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
Hi i want to covert my UIView to UIImage in particular frame size kindly help me.
I have 'UITableView` which is added as subview of 'UIScrollView' for horizontal scroll, my table view frame size is (0, 0, 12000, 768).
I want to convert the current visible are of my UITableView as UIImage after scrolling.
Example:
if i scrolled my table view horizontally some distance means that current visible are is (150,0,1200,768) that means full device screen.
if i use the following code:
UIGraphicsBeginImageContext(self.frame.size);
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *backgroundImage = UIGraphicsGetImageFromCurrentImageContext();
its capturing always the frame size of (0, 0, 1200, 768) only.
so, how can i set the origin of image capturing.
Kindly help me out.... Thanks in advance....
- (UIImage *)rasterizedImageInView:(UIView *)view atRect:(CGRect)rect {
UIGraphicsBeginImageContextWithOptions(rect.size, view.opaque, 0.0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(context, -rect.origin.x, -rect.origin.y);
[view.layer renderInContext:context];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
This will allow you to capture a UIImage from a particular region within a UIView as defined by a CGRect.
CGRect rect = [self.view bounds];
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[self.view.layer renderInContext:context];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Try this.
UIView *viewprint=[[UIView alloc] initWithFrame:CGRectMake(0, 0, width, height)];
viewprint.backgroundColor=[UIColor whiteColor];
tableView.frame = CGRectMake(0, 0, width, height);
[viewprint addSubview:tableView];
UIGraphicsBeginImageContext(viewprint.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[view.layer renderInContext:context];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
I have the self.view, but I only want to capture 300x320 of it.
got this code:
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
UIImage * imgPrintScreen = [[UIImage alloc]init];
imgPrintScreen = viewImage;
What do I need to change here in order to do so?
Thanks allot!
Just change the size that you want to capture, instead of using the entire bounds, use the size you want. The render will start at the origin of the view and be clipped when it falls outside the bounds. If you need to change where the view is actually clipped, simply translate the context after starting the image context:
UIGraphicsBeginImageContextWithOptions(CGSizeMake(300, 320), YES, 0.);
[self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
If your view was, for example, 600x320 and you wanted to capture the middle 300 points in width, you'd translate the context 150 points to the left:
UIGraphicsBeginImageContextWithOptions(CGSizeMake(300, 320), YES, 0.);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(context, -150.f, 0.f);
[self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
I have an App that takes a screenshot of a UIImageView with the following code:
-(IBAction) screenShot: (id) sender{
UIGraphicsBeginImageContext(sshot.frame.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage,nil, nil, nil);
}
This works well but I need to be able to position where I take the screenshot basically I need to grad only a third of the screen (center portion). I tried using
UIGraphicsBeginImageContext(CGSize 150,150);
But have found that every thing is taken from 0,0 coordinates, has anyone any idea how to position this correctly.
Well the screenshot is taken from a canvas you draw.
So instead of drawing your layer in the whole context, with a reference to top left corner, you will draw it where you want to take the screenshot....
//first we will make an UIImage from your view
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *sourceImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//now we will position the image, X/Y away from top left corner to get the portion we want
UIGraphicsBeginImageContext(sshot.frame.size);
[sourceImage drawAtPoint:CGPointMake(-50, -100)];
UIImage *croppedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(croppedImage,nil, nil, nil);
From this
UIGraphicsBeginImageContext(sshot.frame.size);
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(c, 150, 150); // <-- shift everything up to required position when drawing.
[self.view.layer renderInContext:c];
UIImage* viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
Use this method to crop if u have image with specfic rect to crop:
-(UIImage *)cropImage:(UIImage *)image rect:(CGRect)cropRect
{
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], cropRect);
UIImage *img = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return img;
}
Use like this:
UIImage *img = [self cropImage:viewImage rect:CGRectMake(150,150,100,100)]; //example
If you like you can refer this code.
In this example you can get the image covered by the rect from any position and any zoom scale.
Happy Coding :)
Some extracted code for reference is as below
Main function or code used to crop the photo
- (UIImage *) croppedPhoto
{
CGFloat ox = self.scrollView.contentOffset.x;
CGFloat oy = self.scrollView.contentOffset.y;
CGFloat zoomScale = self.scrollView.zoomScale;
CGFloat cx = (ox + self.cropRectangleButton.frame.origin.x + 15.0f) * 2.0f / zoomScale;
CGFloat cy = (oy + self.cropRectangleButton.frame.origin.y + 15.0f) * 2.0f / zoomScale;
CGFloat cw = 300.0f / zoomScale;
CGFloat ch = 300.0f / zoomScale;
CGRect cropRect = CGRectMake(cx, cy, cw, ch);
NSLog(#"---------- cropRect: %#", NSStringFromCGRect(cropRect));
NSLog(#"--- self.photo.size: %#", NSStringFromCGSize(self.photo.size));
CGImageRef imageRef = CGImageCreateWithImageInRect([self.photo CGImage], cropRect);
UIImage *result = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
NSLog(#"------- result.size: %#", NSStringFromCGSize(result.size));
return result;
}
The details how to use the example is given here.
Enjoy Coding :)