I have placed one label on view and view's frame is CGRectMake(0,0,270,203). Now I have to take screen shot of view with CGRectMake(0,0,800,600). So I have to convert label from old rect to new rect.
here is code which I used to take screen shot:
CGRect rect = [view bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[view.layer renderInContext:context];
UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Here is the code which I used to convert point:
CGRect f = [view convertRect:lblMessage.frame fromView:viewMessage];
But I am not able to get actual position from label in new image. Can anyone help where I am wrong.
Here I have attached image for more clarification.
In small view, I have add one label and I have to convert label's frame as per big image view.
Thanks,
+(UIImage*)screenShotOf:(UIView*)view atScale:(CGFloat)scale
{
UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, scale);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
Here You need to adjust the scale property as you needed.
You could do something like this:
-(CGPoint) convertPoint: (CGPoint) point fromRect: (CGRect) fromRect toRect: (CGRect) toRect {
return (CGPoint){
(toRect.size.width/fromRect.size.width) * point.x,
(toRect.size.height/fromRect.size.height) * point.y
};
}
Related
After going through this link, issue with my code is that output image is unable to set proper x and y values as cropped image seems to have 0 and 0 in the resultant image irrespective to where I zoom (or where the scroll offset is calculated). Here's what I tried.
- (IBAction)crop:(id)sender
{
float zoomScale = 1.0f / [self.scroll zoomScale];
CGRect rect;
NSLog(#"contentOffset is :%f,%f",[self.scroll contentOffset].x,[self.scroll contentOffset].y);
rect.origin.x = self.scroll.contentOffset.x * zoomScale;
rect.origin.y = self.scroll.contentOffset.y * zoomScale;
rect.size.width = self.scroll.bounds.size.width * zoomScale;
rect.size.height = self.scroll.bounds.size.height * zoomScale;
UIGraphicsBeginImageContextWithOptions( CGSizeMake(rect.size.width, rect.size.height),
NO,
0.);
NSLog(#"rect offset is :%f,%f",rect.origin.x,rect.origin.y);
CGPoint point = CGPointMake(-rect.origin.x, -rect.origin.y); **//even though above NSLog have some values, but output image is unable to set proper x and y values as cropped image seems to have 0 and 0 in the resultant image.**
[[self.imagV image] drawAtPoint:point
blendMode:kCGBlendModeCopy
alpha:1];
self.croppedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
DTImageViewController *imageViewController = [[DTImageViewController alloc] initWithNibName:#"DTImageViewController" bundle:nil];
imageViewController.image = self.croppedImage;
[self.navigationController pushViewController:imageViewController animated:YES];
}
Similar code as already posted but just taking whole UIScrollView bounds without passing a CGRect
-(void)takeScreenShotOfScrollView
{
UIGraphicsBeginImageContextWithOptions(scrollView.bounds.size, YES, [UIScreen mainScreen].scale);
CGPoint offset = scrollView.contentOffset;
CGContextTranslateCTM(UIGraphicsGetCurrentContext(), -offset.x, -offset.y);
[scrollView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
img = [SDImageHelper imageWithImage:img_image scaledToSize:CGSizeMake(769, 495)];
}
BONUS:
The cropping method
+(UIImage*)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize
{
//UIGraphicsBeginImageContext(newSize);
// In next line, pass 0.0 to use the current device's pixel scaling factor (and thus account for Retina resolution).
// Pass 1.0 to force exact pixel size.
UIGraphicsBeginImageContextWithOptions(newSize, NO, 0.0);
[image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
I'm using the following code for this and it does exactly what expected:
- (UIImage *) croppedImageOfView:(UIView *) view withFrame:(CGRect) rect
{
UIGraphicsBeginImageContextWithOptions(rect.size,NO,0.0);
CGContextTranslateCTM(UIGraphicsGetCurrentContext(), -rect.origin.x, -rect.origin.y);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *visibleScrollViewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return visibleScrollViewImage;
}
- (void) crop
{
CGRect neededRect = CGRectMake(50,50,100,100);
UIImage *image = [self croppedImageOfView:_scrollView withFrame:neededRect];
}
Works well even if content is zoomed, the only thing that must be calculated wisely is needed area CGRect.
In my app I have a scrollview with an added subview called allView.
In the scrollview delegate methods I am applying value of the current transformation of the scrollview's subview to another view called paint view
paintView.transform = allView.transform
and save it to the disk.
The image that is created in result of that process looks different than the one on the screen. Why? How can I fix it?
View Controller
- (void)scrollViewDidScroll:(UIScrollView *)scrollView; {
self.paintView.transform =self.allView.transform;
[self.paintView setNeedsDisplay];
}
- (void)scrollViewDidZoom:(UIScrollView *)scrollView{
self.backgroundView.transform = self.allView.transform;
[self.paintView setNeedsDisplay];
}
Paint View
Inside the PaintView's draw rect I am trying to apply transformation from the scroll view and
- (void)drawRect:(CGRect)rect
{
// Drawing code
// Draw on the screen
CGContextRef ctx1 =UIGraphicsGetCurrentContext();
CGContextConcatCTM(ctx1, self.transform);
CGColorRef wh = [[UIColor redColor]CGColor];
CGContextSetStrokeColorWithColor(ctx1, wh);
CGContextMoveToPoint(ctx1, 0, 0);
CGContextAddLineToPoint(ctx1, 200, 200);
CGContextStrokePath(ctx1);
// Apply scroll view's transformation
CGRect r = CGRectApplyAffineTransform(rect,self.transform );
//that gives a resized image
UIGraphicsBeginImageContextWithOptions(r.size, NO, 0.0);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextConcatCTM(ctx, self.transform);
// stroke and so on
CGContextSetStrokeColorWithColor(ctx, wh);
CGContextMoveToPoint(ctx, 0, 0);
CGContextAddLineToPoint(ctx, 200, 200);
CGContextStrokePath(ctx);
Getting image with entire content.
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
//Clipping the image
CGImageRef cgImg = CGImageCreateWithImageInRect(image.CGImage, rect);
UIImage *img = [UIImage imageWithCGImage:cgImg];
NSData * d = UIImageJPEGRepresentation(img, 0.8);
//saving the image (for debugging)
[self save:d];
UIGraphicsEndImageContext();
}
iOS Simulator
Image saved to the disk
It may be a little bit hard to diagnose the problem here without being able to have running code. However, I think the problem may be on these lines where you are clipping the image:
// Clipping the image
CGImageRef cgImg = CGImageCreateWithImageInRect(image.CGImage, rect);
UIImage *img = [UIImage imageWithCGImage:cgImg];
I think you actually just want to get the scroll view's visible rect, which would be scrollView.frame rather than the subview that fills the scroll view's entire contentSize. So, using some way (such as a property on paintView such as a visibleFrame), I would revise the lines to be something like this:
// Clipping the image
CGImageRef cgImg = CGImageCreateWithImageInRect(image.CGImage, self.visibleFrame);
UIImage *img = [UIImage imageWithCGImage:cgImg];
Hope this helps you get passed this issue!
I am trying to generate screenshot of UIView which having subview with CATransform3DMakeRotation. Screenshot is generated but it doesn't contain Rotation.
Is it possible to achieve this?
Actual View:
ScreenShot Image
Using following call to Flip the view horizontally...
currentView.layer.transform = CATransform3DConcat(currentView.layer.transform,CATransform3DMakeRotation(M_PI, 0.0, 1.0, 0.0f));
Code for taking screen shot
+ (UIImage *) imageWithView:(UIView *)view
{
CGSize screenDimensions = view.bounds.size;
// Create a graphics context with the target size
// (last parameter takes scale into account)
UIGraphicsBeginImageContextWithOptions(screenDimensions, NO, 0);
// Render the view to a new context
CGContextRef context = UIGraphicsGetCurrentContext();
[view.layer renderInContext:context];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
The "renderInContext" only works for Affine transform. So convert the 3D transform into affine transform like this
currentView.layer.affineTransform = CATransform3DGetAffineTransform(CATransform3DConcat(currentView.layer.transform,CATransform3DMakeRotation(M_PI, 0.0, 1.0, 0.0f)));
Try this code
CGSize newSize = CGSizeMake(yourview.frame.size.width , yourview.frame.size.height);
UIGraphicsBeginImageContextWithOptions(newSize,YES,2.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetInterpolationQuality(context, kCGInterpolationHigh);
[yourview.layer renderInContext:context];
[yourview drawRect:yourview.frame];
UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
This might work, try it:
CGRect grabRect = CGRectMake(40,40,300,200);
//for retina displays
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(grabRect.size, NO, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(grabRect.size);
}
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, -grabRect.origin.x, -grabRect.origin.y);
[self.view.layer renderInContext:ctx];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
i have achieved this in one of my application by doing a little tweak like first i capture the whole screen's screen shot and then crop it with the desired frame i need here is a sample code from my app.
- (UIImage *) croppedPhoto
{
[imgcropRectangle setHidden:TRUE];
UIGraphicsBeginImageContext(self.view.frame.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// Create bitmap image from original image data,
// using rectangle to specify desired crop area
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], self.imgcropRectangle.frame);
UIImage *result = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
[imgcropRectangle setHidden:FALSE];
return result;
}
here imgcropRectangle is the UIImageView's object that defines my desired rectangle so i use it's frame for cropping from full screen to desired output. Hope it will help you :)
Try rendering view.layer.presentationLayer instead of view.layer
use this and before passing the view check its subviews :
+ (UIImage *) imageWithView:(UIView *)view
{
UIGraphicsBeginImageContext(CGSizeMake(view.frame.size.width, view.frame.size.height));
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return viewImage
}
I'm using this code to take a Snapshot of the UIScrollView . My problem is that the snap shot will always take the 1.0f zoomscale of the UIScrollView While I want to snapshot the all content in the UIScrollView. How can I accomplish this?
CGRect rect = [viewToCapture bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[viewToCapture.layer renderInContext:context];
UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return capturedImage;
You can have a look at this below url :
https://stackoverflow.com/a/15804107/1443976
I want to merge 2 image in 2 UIImageView into 1 image with "correct" position, angle, ratio scale as I see on screen.
In my project, there are 2 UIImageView
- imageView is the main UIImageView
- topImageView is the overlay UIImageView that can be drag, rotate, scale
I can save image merged by draw 2 images but wrong position, angle, ratio scale.
This is my code:
UIImage *img = topImageView.image;
UIImage *bottomImg = self.imageView.image;
CGSize bounds = self.imageView.image.size;
UIGraphicsBeginImageContext(bounds);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, topImageView.image.size.width * 0.5, topImageView.image.size.height * 0.5);
CGFloat angle = atan2(topImageView.transform.b, topImageView.transform.a);
CGContextRotateCTM(ctx, angle);
[topImageView.image drawInRect:CGRectMake(-topImageView.image.size.width * 0.5,
-topImageView.image.size.height * 0.5,
topImageView.image.size.width,
topImageView.image.size.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIGraphicsBeginImageContext(bounds);
[bottomImg drawInRect:CGRectMake(0, 0, bounds.width, bounds.height)];
[newImage drawInRect:CGRectMake(topImageView.frame.origin.x,
topImageView.frame.origin.y,
newImage.size.width,
newImage.size.height)];
UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Any idea to help me? Thanks a lot!
Add both of those images as subviews to a UIView. Do what you need to the images and then take a snapshot of the UIVIew like so:
UIGraphicsBeginImageContext(view.bounds.size);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *MergedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Try This
#pragma mark - Marge two Images
- (UIImage *) addImageToImage:(UIImage *)img withImage2:(UIImage *)img2{
CGSize size = CGSizeMake(imageView.image.size.width, imageView.image.size.height);
UIGraphicsBeginImageContext(size);
CGPoint pointImg1 = CGPointMake(0,0);
[img drawAtPoint:pointImg1];
CGPoint pointImg2 = CGPointMake(0,0);
[img2 drawAtPoint: pointImg2];
UIImage* result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return result;
}
[self addImageToImage:imageView.image withImage2:imageView2.image];