Capturing of Screen shot starting from 0,0 - iphone

I am using following code to make a screen shot
UIGraphicsBeginImageContext(self.view.frame.size);
blendMode:kCGBlendModeClear alpha:1.0];
[self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
return viewImage;
It is working fine but it returns the full screen, and I want a screen shot of a particular Frame, like ( 100,100,200,200), I tried to make changes in:
UIGraphicsBeginImageContext(self.view.frame.size);
But no success.

Try this:
float x = 100;
float y = 100;
CGSize size = CGSizeMake(200,200);
UIGraphicsBeginImageContext(size);
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(c, -x, -y);
[view.layer renderInContext:c];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

just use three line of code.
UIGraphicsBeginImageContext(CGSizeMake(320, 480));
[self.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *frame= UIGraphicsGetImageFromCurrentImageContext();

Related

Take screenshot of a selected frame in a UIView

How to take screenshot of a selected frame in UIView and set it as a UIImage?
I Also tried this
UIGraphicsBeginImageContext(CGSizeMake(width,height));
CGContextRef context = UIGraphicsGetCurrentContext();
[imageview.layer renderInContext:context];
UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
you can do like this
CGRect rect = [captureView bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[captureView.layer renderInContext:context];
UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext()

how to convert the part of UIView into UIImage and display it in imageView

I have a view in which i am drawing the signature i want that the signature part of the view should be converted as UIImage and then display it in UIImageView here is the code which i got from net i am using for converting
UIGraphicsBeginImageContext(signatureView.bounds.size);
[signatureView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
logoImageView.image=img;
UIGraphicsEndImageContext();
Try this hope will help you.
- (UIImage *) getUIImageWithmyView:(UImyView *)myView
{
UIGraphicsBeginImageContextWithOptions(myView.bounds.size, myView.opaque, 0.0);
[myView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * myImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return myImage;
}
use my bellow method...
- (UIImage *)captureView {
//hide controls if needed
CGRect rect = [signetureView bounds];//use your signature view's Rect means Frame;
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[self.view.layer renderInContext:context];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
you can call this above method like bellow...
UIImage *tempImageSave=[self captureView];
try this:
UIGraphicsBeginImageContext(signatureView.bounds.size);
[signatureView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
logoImageView.image=img;
first endimagecontext and after that set/use that image in imageview

UIImage screenshot loses its quality

I am merging two images and then I take a screenshot by applying this code:
UIGraphicsBeginImageContext(size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
img_AddText=viewImage;
[dragView removeFromSuperview];
imgV_SelectedImg.image=nil;
imgV_SelectedImg.image=img_AddText;
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
The problem is that when the final image loses its quality it blurs.
Try using the withOptions version of UIGraphicsBeginImageContext
UIGraphicsBeginImageContextWithOptions(size, NO, 0.0);
i got the snapshot with good quality and particular location of screen. By this code.
-(UIImage *)takeScreenShot
{
CGRect grabRect;
grabRect = CGRectMake(0,70,320,260);
UIGraphicsBeginImageContextWithOptions(grabRect.size, self.view.opaque, 0.0);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, -grabRect.origin.x, -grabRect.origin.y);
[self.view.layer renderInContext:ctx];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return viewImage;
}
it gives me excellent snapshot..
I've made a category on UIImage class that may help you. It goes like this:
+ (UIImage*)imageWithView:(UIView *)view opaque:(BOOL)opaque bgColor:(UIColor*)bgColor{
UIGraphicsBeginImageContextWithOptions(view.bounds.size, opaque, [[UIScreen mainScreen] scale]);
if(!opaque){
[bgColor set];
}
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
It works fine for me. No bluring was detected. Try to use it. If you'll still have it then most likely the problem is in your saving code...
Cheers... :)
UIGraphicsBeginImageContextWithOptions(size, NO, 2.0);
this solve my prblem by increasing scale from 1.0 to 2.0
Did you provide an image for retina display? You should check it. You might be running in a simulator (in retina).

how to take a screen shot from a mapview

In my application i have used mapview. On particular place i can put annotation. i want to take the snap shot of that place with annotation in it.
i tried to implement this.
CGSize size = self.view.bounds.size;
CGRect screensize = CGRectMake(40,40,size.width-240,size.height-400);
UIGraphicsBeginImageContext(screensize.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenshotImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(screenshotImage, nil, nil, nil);
UIGraphicsEndImageContext();
this code takes the snap but it takes the snap from (0,0) coordinates. i want to take the snap from (40,40) coordinates and the size of the image should be 80*80.
How can i do this?
I don't think you can do it directly. Get the entire image and the crop the desired region.
CGSize size = self.view.bounds.size;
CGRect cropRect = CGRectMake(40, 40, 80, 80);
/* Get the entire on screen map as Image */
UIGraphicsBeginImageContext(size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * mapImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
/* Crop the desired region */
CGImageRef imageRef = CGImageCreateWithImageInRect(mapImage.CGImage, cropRect);
UIImage * cropImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
/* Save the cropped image */
UIImageWriteToSavedPhotosAlbum(cropImage, nil, nil, nil);
UIGraphicsEndImageContext();

UIGraphicsBeginImageContext with parameters

I am taking a screenshot in my application. I am able to take the screenshot.
Now I want to take the screenshot by specifying the x and y coordinate. Is that possible?
UIGraphicsBeginImageContext( self.view.bounds.size );
[self.view.layer renderInContext:UIGraphicsGetCurrentContext( )];
UIImage* aImage = UIGraphicsGetImageFromCurrentImageContext( );
UIGraphicsBeginImageContext(self.view.bounds.size);
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(c, 0, -40); // <-- shift everything up by 40px when drawing.
[self.view.layer renderInContext:c];
UIImage* viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
If you're using a newer retina display device, your code should factor in the resolution by using UIGraphicsBeginImageContextWithOptions instead of UIGraphicsBeginImageContext:
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size,YES,2.0);
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(c, 0, -40); // <-- shift everything up by 40px when drawing.
[self.view.layer renderInContext:c];
UIImage* viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
This will render the retina display image context.
Just do something like this, way easier than all those complex calculations
+ (UIImage *)imageWithView:(UIView *)view {
UIGraphicsBeginImageContextWithOptions([view bounds].size, NO, [[UIScreen mainScreen] scale]);
[[view layer] renderInContext:UIGraphicsGetCurrentContext()];
UIImage *result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return result;
}
Here is Swift version
//Capture Screen
func capture()->UIImage {
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, false, UIScreen.mainScreen().scale)
self.view.layer.renderInContext(UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
swift version
UIGraphicsBeginImageContext(self.view.bounds.size)
let image: CGContextRef = UIGraphicsGetCurrentContext()!
CGContextTranslateCTM(image, 0, -40)
// <-- shift everything up by 40px when drawing.
self.view.layer.renderInContext(image)
let viewImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil)