In order to make a Slide Show, I installed the KASlideShow pod, which is perfect. On the iphone 5S, my Slideshow took all the width (What I wanted), but, when it comes to test the app on the iPhone 6, it takes only 3/4 of the screen.
I tried to scale the UIImage using this method :
CGRect rect = CGRectMake(0,0, width, height);
UIGraphicsBeginImageContext( rect.size );
[originialImage drawInRect:rect];
UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData *imageData = UIImagePNGRepresentation(finalImage);
UIImage *img=[UIImage imageWithData:imageData];
But it only scales to 3/4, even if I put enormous values. It's as if there was a limit.
I tried to use UIViewContentMode.ScaleAspectFill attribute, but it doesn't do anything.
I do not have more ideas to test :/
Thanks for your help.
Related
I have an image with multiple icons, and I have the position and the size of the icon that I want to show.
The question is, how can I show just part of an image in a UIImageView so I can show only the icon that I want to?
Is it possible to show the icon correctly in 1x, 2x, and 3x, even if the image gets a bit pixelated?
You can crop a part of the image and create a new UIImage from it with CGImageCreateWithImageInRect:
CGRect cropRect = CGRectMake(x,y,width,height); //Calculate the rect you'd like to show
CGImageRef imageRef = CGImageCreateWithImageInRect(originalImage.CGImage, cropRect);
UIImage* outImage = [UIImage imageWithCGImage:imageRef scale:originalImage.scale orientation:originalImage.imageOrientation];
CGImageRelease(imageRef);
I'm trying to save the currently shown views on my iOS device for a certain app, and this is working properly. But I've got a problem as soon as I'm trying to save a UIImageView in Landscape orientation.
See the following image that describes my problem:
I'm using Auto layout for this app, and it runs on both iPhone and iPad. It seems like the ImageView is always saved as shown in portrait mode, and I'm a little bit stuck right now.
This is the code I use:
CGSize frameSize = self.view.frame.size;
if (UIInterfaceOrientationIsLandscape(self.interfaceOrientation)) {
frameSize = CGSizeMake(self.view.frame.size.height, self.view.frame.size.width);
}
UIGraphicsBeginImageContextWithOptions(frameSize, NO, 0.0);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGFloat scale = CGRectGetWidth(self.view.frame) / CGRectGetWidth(self.view.bounds);
CGContextScaleCTM(ctx, scale, scale);
[self.view.layer renderInContext:ctx];
[self.delegate photoSaved:UIGraphicsGetImageFromCurrentImageContext()];
UIGraphicsEndImageContext();
Looking forward to your help!
I still have no idea what your exact issue is but using your screenshot code makes a bit strange image (not rotated or anything though, just too small). Can you try this code instead please.
+ (UIImage *)imageFromView:(UIView *)view {
UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, .0f);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
Other then that you must understand there is a huge difference between UIImage and CGImage as the UIImage includes the orientation while CGImage does not. When dealing with image transformations it is usually with the CGImage and getting its width or height will discard the orientation. That means a CGImage will have flipped dimensions when its orientation is not up (UIImageOrientationUp). But usually when dealing with such images you create a CGImage from the context and then use [UIImage imageWithCGImage:ref scale:1.0f orientation:originalOrientation]. Only if you wish to explicitly rotate the image so it has no orientation (being UIImageOrientationUp) you need to rotate and translate the image and draw it onto the context.
Anyway, this orientation issues are quite fixed by now, UIImagePNGRepresentation respects the orientation and you have an image constructor from the CGImage already written above which is what used to be missing in the past if I remember correctly.
I have a UIView and I want to save it's content to an image, I successfully did that using UIGraphicsBeginImageContext and UIGraphicsGetImageFromCurrentImageContext() but the problem is that the image quality is reduced. Is there a way to take a screenshot/save UIView content to an image without reducing it's quality?
Here's a snippet of my code:
UIGraphicsBeginImageContext(self.myView.frame.size);
[self.myview.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Try Following Code :
UIGraphicsBeginImageContextWithOptions(YourView.bounds.size, NO, 0);
[YourView drawViewHierarchyInRect:YourView.bounds afterScreenUpdates:YES];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
This code working Awsome...!!!
Mital Solanki’s answer is a fine solution, but the root of the problem is that your view is on a retina screen (so has a scale factor of 2) and you are creating a graphics context with a scale factor of 1. The documentation for UIGraphicsBeginImageContext states:
This function is equivalent to calling the UIGraphicsBeginImageContextWithOptions function with the opaque parameter set to NO and a scale factor of 1.0.
Instead use UIGraphicsBeginImageContextWithOptions with a scale of 0, which is equivalent to passing a scale of [[UIScreen mainScreen] scale].
This question already has answers here:
The simplest way to resize an UIImage?
(34 answers)
Closed 9 years ago.
I've created a UIImageView which contains an image with a high resolution. The problem is that the resolution of that image is too high to put into the imageView. The size of the imageView is 92 x 91 (so it's small). It contains an UIImage, whose resolution is too high so it looks ugly in the UIImageView.
So how can I reduce the resolution of that UIImage?
My code for the UIImageView:
UIImageView *myImageView = [[UIImageView alloc] initWithImage:[UIImage imageWithContentsOfFile:pngFilePath]];
myImageView.frame = CGRectMake(212.0, 27, 92,91);
have a look at this
https://stackoverflow.com/a/2658801
This will help you to resize your image according to your need
Add method to your code and call like this
UIImage *myImage =[UIImage imageWithContentsOfFile:pngFilePath];
UIImage *newImage =[UIImage imageWithImage:myImage scaledToSize:CGSizeMake(92,91)];
You can resize an image using this method that returns a resized image :
-(UIImage *)imageWithImage:(UIImage *)image scaledToSize:(CGSize)newSize {
UIGraphicsBeginImageContextWithOptions(newSize, NO, 0.0);
// Here pass new size you need
[image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
Hope it helps you.
try with this
myImageView.contentMode = UIViewContentModeScaleToFill;
You need to downsize the image, which will reduce the resolution, make it easier to store. I actually wrote a class (building on some stuff from SO) that does just that. It's on my github, take a look:
https://github.com/pavlovonline/UIImageResizer
the main method is
-(UIImage*)resizeImage:(UIImage*)image toSize:(CGFloat)size
so you give this method the size to which you want to downsize your image. If the height is greater than the width, it will auto-calculate the middle and give you a perfectly centered square. Same for width being greater than height. If you need an image that is not square, make your own adjustments.
so you'll get back a downsized UIImage which you can then put into your UIImageView. Save some memory too.
Yep as the title says I need to take a cropped snapshot of my app.
I want to cut top of the screenshot little bit (%20) I already have a code which I used to take a snapshot and send it to facebook and its working but its taking the photo of all of the screen so how can tell my code to ignore the %20 percent of the screen.Maybe with height and width also I looked some questions in the stack overflow and manage to slide my screenshot so I get rid of the unwanted part at the top but this time at the bottom huge white area appeared so it didnt solve my problem.
Here is my snapshot code
UIGraphicsBeginImageContext(self.ekran.bounds.size);
[self.ekran.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
A method to crop the image, that accepts any frame to crop the image against
- (UIImage *)cropImage:(UIImage *)imageToCrop toRect:(CGRect)rect
{
CGImageRef imageRef = CGImageCreateWithImageInRect([imageToCrop CGImage], rect);
UIImage *cropped = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return cropped;
}
Use it as follows:
UIGraphicsBeginImageContext(self.ekran.bounds.size);
[self.ekran.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGFloat imgHight = resultingImage.size.height;
// Create a frame that crops the top 20% of the image
CGRect* imageFrame = CGRectMake(0, imgHight - (imgHight*0.8), width, imgHight*0.8);
resultingImage = [self cropImage:resultingImage toRect:imageFrame];