I want a screenshot of the image on the screen saved into the saved photo library.
Considering a check for retina display use the following code snippet:
#import <QuartzCore/QuartzCore.h>
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(self.window.bounds.size, NO, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(self.window.bounds.size);
}
[self.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData *imageData = UIImagePNGRepresentation(image);
if (imageData) {
[imageData writeToFile:#"screenshot.png" atomically:YES];
} else {
NSLog(#"error while taking screenshot");
}
Below method works for OPENGL objects also
//iOS7 or above
- (UIImage *) screenshot {
CGSize size = CGSizeMake(your_width, your_height);
UIGraphicsBeginImageContextWithOptions(size, NO, [UIScreen mainScreen].scale);
CGRect rec = CGRectMake(0, 0, your_width, your_height);
[_viewController.view drawViewHierarchyInRect:rec afterScreenUpdates:YES];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, self.view.opaque, 0.0);
[self.myView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData *imageData = UIImageJPEGRepresentation(image, 1.0 ); //you can use PNG too
[imageData writeToFile:#"image1.jpeg" atomically:YES];
- (UIImage*) getGLScreenshot {
NSInteger myDataLength = 320 * 480 * 4;
// allocate array and read pixels into it.
GLubyte *buffer = (GLubyte *) malloc(myDataLength);
glReadPixels(0, 0, 320, 480, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
// gl renders "upside down" so swap top to bottom into new array.
// there's gotta be a better way, but this works.
GLubyte *buffer2 = (GLubyte *) malloc(myDataLength);
for(int y = 0; y <480; y++)
{
for(int x = 0; x <320 * 4; x++)
{
buffer2[(479 - y) * 320 * 4 + x] = buffer[y * 4 * 320 + x];
}
}
// make data provider with data.
CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer2, myDataLength, NULL);
// prep the ingredients
int bitsPerComponent = 8;
int bitsPerPixel = 32;
int bytesPerRow = 4 * 320;
CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
// make the cgimage
CGImageRef imageRef = CGImageCreate(320, 480, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);
// then make the uiimage from that
UIImage *myImage = [UIImage imageWithCGImage:imageRef];
return myImage;
}
- (void)saveGLScreenshotToPhotosAlbum {
UIImageWriteToSavedPhotosAlbum([self getGLScreenshot], nil, nil, nil);
}
Source.
IN SWIFT
func captureScreen() -> UIImage
{
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, false, 0);
self.view.drawViewHierarchyInRect(view.bounds, afterScreenUpdates: true)
let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
As of iOS10, this gets a bit simpler. UIKit comes with UIGraphicsImageRender that allows you to
... accomplish drawing tasks, without having to handle configuration such as color depth and image scale, or manage Core Graphics contexts
Apple Docs - UIGraphicsImageRenderer
So you can now do something like this:
let renderer = UIGraphicsImageRenderer(size: someView.bounds.size)
let image = renderer.image(actions: { context in
someView.drawHierarchy(in: someView.bounds, afterScreenUpdates: true)
})
Many of the answers here worked for me in most cases. But when trying to take a snapshot of an ARSCNView, I was only able to do it using the method described above. Although it might be worth noting that at this time, ARKit is still in beta and Xcode is in beta 4
See this post it looks like you can use UIGetScreenImage() for now.
This will save a screenshot and as well return the screenshot too.
-(UIImage *)capture{
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *imageView = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(imageView, nil, nil, nil); //if you need to save
return imageView;
}
I think the following snippet would help if you want to take a full screen(except for status bar),just replace AppDelegate with your app delegate name if necessary.
- (UIImage *)captureFullScreen {
AppDelegate *_appDelegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)]) {
// for retina-display
UIGraphicsBeginImageContextWithOptions(_appDelegate.window.bounds.size, NO, [UIScreen mainScreen].scale);
[_appDelegate.window drawViewHierarchyInRect:_appDelegate.window.bounds afterScreenUpdates:NO];
} else {
// non-retina-display
UIGraphicsBeginImageContext(_bodyView.bounds.size);
[_appDelegate.window drawViewHierarchyInRect:_appDelegate.window.bounds afterScreenUpdates:NO];
}
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
I couldn't find an answer with Swift 3 implementation. So here it goes.
static func screenshotOf(window: UIWindow) -> UIImage? {
UIGraphicsBeginImageContextWithOptions(window.bounds.size, true, UIScreen.main.scale)
guard let currentContext = UIGraphicsGetCurrentContext() else {
return nil
}
window.layer.render(in: currentContext)
guard let image = UIGraphicsGetImageFromCurrentImageContext() else {
UIGraphicsEndImageContext()
return nil
}
UIGraphicsEndImageContext()
return image
}
This will work with swift 4.2, the screenshot will be saved in library, but please don't forget to edit the info.plist # NSPhotoLibraryAddUsageDescription :
#IBAction func takeScreenshot(_ sender: UIButton) {
//Start full Screenshot
print("full Screenshot")
UIGraphicsBeginImageContext(card.frame.size)
view.layer.render(in: UIGraphicsGetCurrentContext()!)
var sourceImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIImageWriteToSavedPhotosAlbum(sourceImage!, nil, nil, nil)
//Start partial Screenshot
print("partial Screenshot")
UIGraphicsBeginImageContext(card.frame.size)
sourceImage?.draw(at: CGPoint(x:-25,y:-100)) //the screenshot starts at -25, -100
var croppedImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIImageWriteToSavedPhotosAlbum(croppedImage!, nil, nil, nil)
}
I'm answering this question as it's a highly viewed, and there are many answers out there plus there's Swift and Obj-C.
Disclaimer This is not my code, nor my answers, this is only to help people that land here find a quick answer. There are links to the original answers to give credit where credit is due!! Please honor the original answers with a +1 if you use their answer!
Using QuartzCore
#import <QuartzCore/QuartzCore.h>
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(self.window.bounds.size, NO, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(self.window.bounds.size);
}
[self.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData *imageData = UIImagePNGRepresentation(image);
if (imageData) {
[imageData writeToFile:#"screenshot.png" atomically:YES];
} else {
NSLog(#"error while taking screenshot");
}
In Swift
func captureScreen() -> UIImage
{
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, false, 0);
self.view.drawViewHierarchyInRect(view.bounds, afterScreenUpdates: true)
let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
Note: As the nature with programming, updates may need to be done so please edit or let me know! *Also if I failed to include an answer/method worth including feel free to let me know as well!
For iOS 7.0 or above..
If you want to take screenshots of view say(myView), you can do this with single line:
[myView snapshotViewAfterScreenUpdates:NO];
Get Screenshot From View
-(UIImage *)getScreenshotImage {
if ([[UIScreen mainScreen] scale] == 2.0) {
UIGraphicsBeginImageContextWithOptions(self.view.frame.size, FALSE, 2.0);
} else {
UIGraphicsBeginImageContextWithOptions(self.view.frame.size, FALSE, 1.0);
}
[self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return result;
}
Save Image to Photos
UIImageWriteToSavedPhotosAlbum(YOUR_IMAGE, nil, nil, nil);
How-To
UIImageWriteToSavedPhotosAlbum([self getScreenshotImage], nil, nil, nil);
Two options available at bellow site:
OPTION 1: using UIWindow (tried and work perfectly)
// create graphics context with screen size
CGRect screenRect = [[UIScreen mainScreen] bounds];
UIGraphicsBeginImageContext(screenRect.size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
[[UIColor blackColor] set];
CGContextFillRect(ctx, screenRect);
// grab reference to our window
UIWindow *window = [UIApplication sharedApplication].keyWindow;
// transfer content into our context
[window.layer renderInContext:ctx];
UIImage *screengrab = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
OPTION 2: using UIView
// grab reference to the view you'd like to capture
UIView *wholeScreen = self.splitViewController.view;
// define the size and grab a UIImage from it
UIGraphicsBeginImageContextWithOptions(wholeScreen.bounds.size, wholeScreen.opaque, 0.0);
[wholeScreen.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screengrab = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
For retina screen (as DenNukem answer)
// grab reference to our window
UIWindow *window = [UIApplication sharedApplication].keyWindow;
// create graphics context with screen size
CGRect screenRect = [[UIScreen mainScreen] bounds];
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(screenRect.size, NO, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(screenRect.size);
[window.layer renderInContext:UIGraphicsGetCurrentContext()];
}
for more detail:
http://pinkstone.co.uk/how-to-take-a-screeshot-in-ios-programmatically/
Get Screenshot From View :
- (UIImage *)takeSnapshotView {
CGRect rect = [myView bounds];//Here you can change your view with myView
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[myView.layer renderInContext:context];
UIImage *capturedScreen = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return capturedScreen;//capturedScreen is the image of your view
}
Hope, this is what you're looking for. Any concern get back to me. :)
Another option is to use the Automation tool on instruments. You write a script to put the screen into whatever you state you want, then take the shots. Here is the script I used for one of my apps. Obviously, the details of the script will be different for your app.
var target = UIATarget.localTarget();
var app = target.frontMostApp();
var window = app.mainWindow();
var picker = window.pickers()[0];
var wheel = picker.wheels()[2];
var buttons = window.buttons();
var button1 = buttons.firstWithPredicate("name == 'dateButton1'");
var button2 = buttons.firstWithPredicate("name == 'dateButton2'");
function setYear(picker, year) {
var yearName = year.toString();
var yearWheel = picker.wheels()[2];
yearWheel.selectValue(yearName);
}
function setMonth(picker, monthName) {
var wheel = picker.wheels()[0];
wheel.selectValue(monthName);
}
function setDay(picker, day) {
var wheel = picker.wheels()[1];
var name = day.toString();
wheel.selectValue(name);
}
target.delay(1);
setYear(picker, 2015);
setMonth(picker, "July");
setDay(picker, 4);
button1.tap();
setYear(picker, 2015);
setMonth(picker, "December");
setDay(picker, 25);
target.captureScreenWithName("daysShot1");
var nButtons = buttons.length;
UIALogger.logMessage(nButtons + " buttons");
for (var i=0; i<nButtons; i++) {
UIALogger.logMessage("button " + buttons[i].name());
}
var tabBar = window.tabBars()[0];
var barButtons = tabBar.buttons();
var nBarButtons = barButtons.length;
UIALogger.logMessage(nBarButtons + " buttons on tab bar");
for (var i=0; i<nBarButtons; i++) {
UIALogger.logMessage("button " + barButtons[i].name());
}
var weeksButton = barButtons[1];
var monthsButton = barButtons[2];
var yearsButton = barButtons[3];
target.delay(2);
weeksButton.tap();
target.captureScreenWithName("daysShot2");
target.delay(2);
monthsButton.tap();
target.captureScreenWithName("daysShot3");
target.delay(2);
yearsButton.tap();
target.delay(2);
button2.tap();
target.delay(2);
setYear(picker, 2018);
target.delay(2);
target.captureScreenWithName("daysShot4");
Just a small contribution, I've done this with a button but the pressing also means the button is captured pressed. So first I unhighlight.
- (IBAction)screenShot:(id)sender {
// Unpress screen shot button
screenShotButton.highlighted = NO;
// create graphics context with screen size
CGRect screenRect = [[UIScreen mainScreen] bounds];
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(self.view.bounds.size);
}
CGContextRef ctx = UIGraphicsGetCurrentContext();
[[UIColor blackColor] set];
CGContextFillRect(ctx, screenRect);
// grab reference to our window
UIWindow *window = [UIApplication sharedApplication].keyWindow;
// transfer content into our context
[window.layer renderInContext:ctx];
UIImage *screengrab = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// save screengrab to Camera Roll
UIImageWriteToSavedPhotosAlbum(screengrab, nil, nil, nil);
}
I got the main body of the code from:
http://pinkstone.co.uk/how-to-take-a-screeshot-in-ios-programmatically/
where I used option 1, option 2 didn't seem to work for me. Added the adjustments for Rentina screen sizes from this thread, and the unhighlighting of the screenShotButton. The view I'm using it on is a StoryBoarded screen of buttons and labels and with several UIView added later via the program.
In Swift you can use following code.
if UIScreen.mainScreen().respondsToSelector(Selector("scale")) {
UIGraphicsBeginImageContextWithOptions(self.window!.bounds.size, false, UIScreen.mainScreen().scale)
}
else{
UIGraphicsBeginImageContext(self.window!.bounds.size)
}
self.window?.layer.renderInContext(UIGraphicsGetCurrentContext())
var image : UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
Swift 4:
func makeImage(withView view: UIView) -> UIImage? {
let rect = view.bounds
UIGraphicsBeginImageContextWithOptions(rect.size, true, 0)
guard let context = UIGraphicsGetCurrentContext() else {
assertionFailure()
return nil
}
view.layer.render(in: context)
guard let image = UIGraphicsGetImageFromCurrentImageContext() else {
assertionFailure()
return nil
}
UIGraphicsEndImageContext()
return image
}
Related
Im currently taking screenshot of a UIScrollView as a part of app functionality. but i want to take the screenshot including additional height from the bottom. (UIScrollView+UIImageView)
This is how im taking UIScrollView screenshot now.
UIGraphicsBeginImageContextWithOptions(ScrollView.bounds.size, true, UIScreen.mainScreen().scale)
let offset = ScrollView.contentOffset
CGContextTranslateCTM(UIGraphicsGetCurrentContext(), -offset.x, -offset.y)
ScrollView.layer.renderInContext(UIGraphicsGetCurrentContext())
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
You can implement this:
+ (UIImage *) imageWithView:(UIView *)view
{
UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, 0.0f);
[view drawViewHierarchyInRect:view.bounds afterScreenUpdates:NO];
UIImage * snapshotImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return snapshotImage;
}
where your view parameter should be a content view.
Or you can take 2 shots, one of the ScrollView and another from the ImageView and merge in one:
- (UIImage*)imageByCombiningImage:(UIImage*)firstImage withImage:(UIImage*)secondImage {
UIImage *image = nil;
CGSize newImageSize = CGSizeMake(MAX(firstImage.size.width, secondImage.size.width), MAX(firstImage.size.height, secondImage.size.height));
if (UIGraphicsBeginImageContextWithOptions != NULL) {
UIGraphicsBeginImageContextWithOptions(newImageSize, NO, [[UIScreen mainScreen] scale]);
} else {
UIGraphicsBeginImageContext(newImageSize);
}
[firstImage drawAtPoint:CGPointMake(roundf((newImageSize.width-firstImage.size.width)/2),
roundf((newImageSize.height-firstImage.size.height)/2))];
[secondImage drawAtPoint:CGPointMake(roundf((newImageSize.width-secondImage.size.width)/2),
roundf((newImageSize.height-secondImage.size.height)/2))];
image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
I am new to mobile programming. I am working in H264 video rendering in iOS application using VideoToolBox framework. It has one feature to take snapshot while rendering the video. Whenever I take a snapshot, I get the Black screen only.
I tried this
1. renderInContext,
2. drawViewHierarchyInRect,
3. snapshotViewAfterScreenUpdates method
to capture the rendering the video but returns a Black screen only.
//snapshot coding
UIGraphicsBeginImageContextWithOptions (self.view.bounds.size, YES, 0.0);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *snapshotImage = UIGraphicsGetImageFromCurrentImageContext();
mImageView.image = snapshotImage;
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(snapshotImage,self, #selector(image:didFinishSavingWithError: contextInfo:), nil);
Check this out,
following chunk of code works for me to take screen's snap shot
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)])
UIGraphicsBeginImageContextWithOptions(APP_DELEGATE.window.bounds.size, NO, [[UIScreen mainScreen] scale]);
else
UIGraphicsBeginImageContext(APP_DELEGATE.window.bounds.size);
[APP_DELEGATE.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData * data = UIImagePNGRepresentation(image);
I guess, it will help you. let me know if so
I've not worked with video yet, but a simple snapshot of UIView with subViews on it works fine
+ (UIImage *)makeSnapShot:(UIView *)view image:(UIImageView *)imageView
{
CGFloat offset_x = /*your_value*/;
CGFloat offset_y = /*your_value*/;
UIGraphicsBeginImageContext(view.bounds.size);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGRect rect = CGRectMake(offset_x, offset_y, imageView.bounds.size.width, imageView.bounds.size.height);
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], rect);
image = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return image;
}
Not sure if this is what you're looking for, but if you need to get a snapshot of the VTDecompressionSession, you can send the CVImageBuffer that you get from the decodeFrame callback into this method to get a UIImage. You can also add your CIContext to the parameters list instead of using the temporaryContext.
+ (UIImage *) UIImageFromCVImageBufferRef:(CVImageBufferRef)imageBuf
{
CIImage *ciImage = [CIImage imageWithCVPixelBuffer:imageBuf];
CIContext *temporaryContext = [CIContext contextWithOptions:nil];
CGImageRef videoImage = [temporaryContext
createCGImage:ciImage
fromRect:CGRectMake(0, 0,
CVPixelBufferGetWidth(imageBuf),
CVPixelBufferGetHeight(imageBuf))];
UIImage *image = [[UIImage alloc] initWithCGImage:videoImage];
CGImageRelease(videoImage);
return image;
}
func takeScreenshot(_ shouldSave: Bool = true) {
var screenshotImage :UIImage?
let layer = UIApplication.shared.keyWindow!.layer
let scale = UIScreen.main.scale
UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale)
self.view.drawHierarchy(in: self.view.bounds, afterScreenUpdates: true)
screenshotImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
if let image = screenshotImage, shouldSave {
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
}
}
Been trying to fix this problem all day to no avail.
Pretty much, I'm taking a screenshot of the view, then trying to crop out the first 50px and a footer. Problem is that when I do this, the result is a little blowed up, and quality is lost. Here's what I wrote, which I think conforms to retina.
-(UIImage *)takeSnapShotAndReturn{
//Take screenshot of whole view
if([[UIScreen mainScreen] respondsToSelector:#selector(scale)]){
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size,NO,[UIScreen mainScreen].scale);
}
else{
UIGraphicsBeginImageContext(self.view.window.bounds.size);
}
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
combinedImage = [self cropOutArea:image withRectangle:CGRectMake(0, 50, 320, 467)];
UIImageWriteToSavedPhotosAlbum(combinedImage, nil, nil, nil);
UIGraphicsEndImageContext();
return image;
}
-(UIImage *)cropOutArea:(UIImage*)image withRectangle:(CGRect)rectangle{
if(image.scale > 1){
rectangle = CGRectMake(rectangle.origin.x * image.scale,
rectangle.origin.y * image.scale,
rectangle.size.width * image.scale,
rectangle.size.height * image.scale);
}
CGImageRef imageRef = CGImageCreateWithImageInRect(image.CGImage, rectangle);
UIImage *result = [UIImage imageWithCGImage:imageRef scale:image.scale orientation:image.imageOrientation];
CGImageRelease(imageRef);
return result;
}
I find cropping extremely confusing!
I'm not sure EXACTLY what you're trying to do, but this may be it .....
-(UIImage *)simplishTopCropAndTo640:(UIImage *)fromImage
// moderately optimised!
{
float shortDimension = fminf(fromImage.size.width, fromImage.size.height);
// 1.use CGImageCreateWithImageInRect to take only the top square...
// 2. use drawInRect (or CGContextDrawImage, same) to scale...
CGRect topSquareOfOriginalRect =
CGRectMake(0,0, shortDimension,shortDimension);
// NOT fromImage.size.width,fromImage.size.width);
CGImageRef topSquareIR = CGImageCreateWithImageInRect(
fromImage.CGImage, topSquareOfOriginalRect);
CGSize size = CGSizeMake( 640,640 );
CGRect sized = CGRectMake(0.0f, 0.0f, size.width, size.height);
UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
CGContextRef cc = UIGraphicsGetCurrentContext();
CGContextSetInterpolationQuality(cc, kCGInterpolationLow);
CGContextTranslateCTM(cc, 0, size.height);
CGContextScaleCTM(cc, 1.0, -1.0);
CGContextDrawImage(cc, sized, topSquareIR );
// arguably, those three lines more simply...
//[[UIImage imageWithCGImage:topSquareIR] drawInRect:sized];
CGImageRelease(topSquareIR);
UIImage *result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
result =
[UIImage imageWithCGImage:result.CGImage
scale:result.scale
orientation: fromImage.imageOrientation];
//consider...something like...
//[UIImage imageWithCGImage:cgimg
// scale:3 orientation:fromImage.imageOrientation];
return result;
}
Consider also this valuable category .....
-(UIImage *)ordinaryCrop:(CGRect)toRect
{
// crops any image, to any rect. you can't beat that
CGImageRef imageRef = CGImageCreateWithImageInRect([self CGImage], toRect);
UIImage *cropped = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return cropped;
}
Finally don't forget this if you're using the camera "the most useful code in the universe!" iOS UIImagePickerController result image orientation after upload
Hope it helps somehow
Try setting this BOOL property before releasing result in cropOutArea.
result.layer.masksToBounds = YES
I am having problems with the following code only takes a photo of my UITableView only and not the entire screen with the navigation and tab bars...
I would like the full screen capturing including navigation and tab bars. Any help greatly appreciated.
- (UIImage*)captureView:(UIView *)view
{
CGRect rect = [[UIScreen mainScreen] bounds];
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[view.layer renderInContext:context];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
The following code worked for me a couple of months ago:
CALayer *layer = [[UIApplication sharedApplication] keyWindow].layer;
CGFloat scale = [UIScreen mainScreen].scale;
UIGraphicsBeginImageContextWithOptions(layer.frame.size, NO, scale);
[layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext();
Swift 3.0 Version if any one needs
func getScreenShot() -> UIImage {
let layer : CALayer = (UIApplication.shared.keyWindow?.layer)!
let scale : CGFloat = UIScreen.main.scale
UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale)
layer.render(in: UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image!
}
in my iPad app, I'd like to make a screenshot of a UIView taking a big part of the screen. Unfortunately, the subviews are pretty deeply nested, so it takes to long to make the screenshot and animate a page curling afterwards.
Is there a faster way than the "usual" one?
UIGraphicsBeginImageContext(self.bounds.size);
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
If possible, I'd like to avoid caching or restructuring my view.
I've found a better method that uses the snapshot API whenever possible.
I hope it helps.
class func screenshot() -> UIImage {
var imageSize = CGSize.zero
let orientation = UIApplication.shared.statusBarOrientation
if UIInterfaceOrientationIsPortrait(orientation) {
imageSize = UIScreen.main.bounds.size
} else {
imageSize = CGSize(width: UIScreen.main.bounds.size.height, height: UIScreen.main.bounds.size.width)
}
UIGraphicsBeginImageContextWithOptions(imageSize, false, 0)
for window in UIApplication.shared.windows {
window.drawHierarchy(in: window.bounds, afterScreenUpdates: true)
}
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image!
}
Wanna know more about iOS 7 Snapshots?
Objective-C version:
+ (UIImage *)screenshot
{
CGSize imageSize = CGSizeZero;
UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
if (UIInterfaceOrientationIsPortrait(orientation)) {
imageSize = [UIScreen mainScreen].bounds.size;
} else {
imageSize = CGSizeMake([UIScreen mainScreen].bounds.size.height, [UIScreen mainScreen].bounds.size.width);
}
UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
CGContextRef context = UIGraphicsGetCurrentContext();
for (UIWindow *window in [[UIApplication sharedApplication] windows]) {
CGContextSaveGState(context);
CGContextTranslateCTM(context, window.center.x, window.center.y);
CGContextConcatCTM(context, window.transform);
CGContextTranslateCTM(context, -window.bounds.size.width * window.layer.anchorPoint.x, -window.bounds.size.height * window.layer.anchorPoint.y);
if (orientation == UIInterfaceOrientationLandscapeLeft) {
CGContextRotateCTM(context, M_PI_2);
CGContextTranslateCTM(context, 0, -imageSize.width);
} else if (orientation == UIInterfaceOrientationLandscapeRight) {
CGContextRotateCTM(context, -M_PI_2);
CGContextTranslateCTM(context, -imageSize.height, 0);
} else if (orientation == UIInterfaceOrientationPortraitUpsideDown) {
CGContextRotateCTM(context, M_PI);
CGContextTranslateCTM(context, -imageSize.width, -imageSize.height);
}
if ([window respondsToSelector:#selector(drawViewHierarchyInRect:afterScreenUpdates:)]) {
[window drawViewHierarchyInRect:window.bounds afterScreenUpdates:YES];
} else {
[window.layer renderInContext:context];
}
CGContextRestoreGState(context);
}
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
EDIT October 3. 2013
Updated to support the new super fast drawViewHierarchyInRect:afterScreenUpdates: method in iOS 7.
No. CALayer's renderInContext: is as far as I know the only way to do this. You could create a UIView category like this, to make it easier for yourself going forward:
UIView+Screenshot.h
#import <UIKit/UIKit.h>
#interface UIView (Screenshot)
- (UIImage*)imageRepresentation;
#end
UIView+Screenshot.m
#import <QuartzCore/QuartzCore.h>
#import "UIView+Screenshot.h"
#implementation UIView (Screenshot)
- (UIImage*)imageRepresentation {
UIGraphicsBeginImageContextWithOptions(self.bounds.size, YES, self.window.screen.scale);
/* iOS 7 */
if ([self respondsToSelector:#selector(drawViewHierarchyInRect:afterScreenUpdates:)])
[self drawViewHierarchyInRect:self.bounds afterScreenUpdates:NO];
else /* iOS 6 */
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage* ret = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return ret;
}
#end
By this you might be able to say [self.view.window imageRepresentation] in a view controller, and get a full screenshot of your app. This might exclude the statusbar though.
EDIT:
And may I add. If you have an UIView with transparent content, and needs an image representation WITH the underlaying content as well, you can grab an image representation of the container view and crop that image, simply by taking the rect of the subview and converting it to the container views coordinate system.
[view convertRect:self.bounds toView:containerView]
To crop see answer to this question: Cropping an UIImage
iOS 7 introduced a new method that allows you to draw a view hierarchy into the current graphics context. This can be used to get an UIImage very fast.
Implemented as category method on UIView:
- (UIImage *)pb_takeSnapshot {
UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, [UIScreen mainScreen].scale);
[self drawViewHierarchyInRect:self.bounds afterScreenUpdates:YES];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
It is considerably faster then the existing renderInContext: method.
UPDATE FOR SWIFT: An extension that does the same:
extension UIView {
func pb_takeSnapshot() -> UIImage {
UIGraphicsBeginImageContextWithOptions(self.bounds.size, false, UIScreen.mainScreen().scale);
self.drawViewHierarchyInRect(self.bounds, afterScreenUpdates: true)
// old style: self.layer.renderInContext(UIGraphicsGetCurrentContext())
let image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
}
I combined the answers to single function which will be running for any iOS versions, even for retina or non-retains devices.
- (UIImage *)screenShot {
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)])
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, [UIScreen mainScreen].scale);
else
UIGraphicsBeginImageContext(self.view.bounds.size);
#ifdef __IPHONE_7_0
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 70000
[self.view drawViewHierarchyInRect:self.view.bounds afterScreenUpdates:YES];
#endif
#else
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
#endif
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
For me setting the InterpolationQuality went a long way.
CGContextSetInterpolationQuality(ctx, kCGInterpolationNone);
If you are snapshotting very detailed images this solution may not be acceptable. If you are snapshotting text you will hardly notice the difference.
This cut down the time to take the snap shot significantly as well as making an image that consumed far less memory.
This is still beneficial with the drawViewHierarchyInRect:afterScreenUpdates: method.
What you’re asking for as an alternative is to read the GPU (since the screen is composited from any number of translucent views), which is an inherently slow operation too.