Show portion of UIImage in UIImageVIew - objective-c

This question might have been answered, but I can't find a solution to my problem after hours of googling.
I have a UIImageView (320*320) in a custom UITableCell with a UIImage (320*320) inside.
When I click on a button, the UIImageView resizes to 320*80 (animated) and the UIImage too.
How could I do to prevent the UIImage from resizing ?
I would like this UIImage to stay but same and show only a portion of this image ( a 320*80 frame with 0/0 origin)
Edit : Cropping
I thought of cropping the image to the right size and then set the UIImageView's image to the fullsize image, but it looks ugly because when the user clicks on the UIImageView, this one is still 320*320 but the UIImage has been set to the cropped one (320*80) so it is streched...
Thanks

I'm doing something similar in one of my apps, when I create the UIImageView object, I set the property contentMode to UIViewContentModeScaleAspectFill, and the clipsToBounds property to YES. Hope this helps.

You can resize the image and then replace the UIImageView image with the resized one.
CGImageRef imageToBeResized = yourImage.CGImage;
CGImageRef partOfImageAsCG = CGImageCreateWithImageInRect(imageToBeResized, CGRectMake(0, 0, 320, 80));
CGRelease(imageToBeResized);
UIImage *resizedImage = [UIImage imageWithCGImage:imageToBeResized];

Maybe you should think about use a UIScrollView with your UIImageView inside. So, you can with its properties to archive the desired behaviour.

Related

Get Image from image View

if we add more than one View to imageView and NSString also. Is it possible to get image from ImageView that contain all images and strings etc?
like this
From what I understand in your question, you have added an ImageView for the building, another for the video symbol (as a subview) and a UILabel (again as a subview) for the time. You want all these to be rendered as a single UIImage. For this, you can use:
UIGraphicsBeginImageContext(imageView.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[imageView.layer renderInContext:context];
UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
The screenshot UIImage will contain your desired image.

Get UIImage from UIImageView with masked subviews

Through Face Detection, I want to blur eyes and mouth of a person. So I have a imageView that contains 3 subviews (2 per eye and the mouth). Each one of these subviews were masked with a PNG shape (with background clear) for avoiding to show rectangle.
My imageView in screen remain so: http://screencast.com/t/ak4SkNXM0I
And I want to obtain the image for storing in another place, so I've tried this:
CGSize size = [imageView bounds].size;
UIGraphicsBeginImageContext(size);
[[imageView layer] renderInContext:UIGraphicsGetCurrentContext()];
UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
But finalImage is an image like this:
http://screencast.com/t/eDlvGqqY
My subViews (eyes and mouth) are not masked as above.
Any idea?
Thanks.
Edit:
I have to use library compatible with ios6
You can check the new API added to iOS7. Try one of the following methods:
snapshotViewAfterScreenUpdates:
resizableSnapshotViewFromRect:afterScreenUpdates:withCapInsets: for resizable image
drawViewHierarchyInRect:afterScreenUpdates:

Draw bezier curve above image of UIImageView

How to draw beziercurve above the image of the UIImageView. I am subclassing UIImageView and drawing circles using UIBezierCurve on the corners of image view. But as soon as i place the image in UIImageView the inside part of circles are overlapped by the image. So is there any solution which lets me draw the UIBezier path on the UIimage of uiimageview ?
You can try subclassing simple UIView and drawing an image yourself using drawInRect: method of UIImage instance. It should look something like this:
- (void)drawRect:(CGRect)dirtyRect {
// note you can get image from anywhere
UIImage *image = [UIImage imageNamed:#"MyImage"];
[image drawInRect:self.bounds];
// now that image is drawn, everything
// past this point will be drawn on top of it
...
}

How can I change the height of an image in Xcode?

I am trying to adjust the height of an image by stretching it.
This is what I've got so far:
-(IBAction)buttonTapped{
UIImage *img = [UIImage imageNamed:#"water.png"];
[water1 setImage:img];
}
-(IBAction)button2Tapped
+ (UIImage*)imageWithImage:(UIImage*)img
scaledToSize:(CGSize)newSize;
{
UIGraphicsBeginImageContext( newSize );
[img drawInRect:CGRectMake(0,2,newSize.width,newSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;}
and this is in my view controller.h
IBOutlet UIImageView *water1;
-(IBAction)buttonTapped;
-(IBAction)button2Tapped;
I am not sure what I need to change to make this correct, or if I should start again with a new way.
I want it so that when I push a button, an image appears, then it resizes it when I push another button.
Thanks for helping!
You can simply change the size of the UIImageView property, in order to get the size you want.
Set the contentMode of the UIImageView to wathever fits your need, and it will automatically resize to the given size (either scaling to fit or stretching).

Overlay an UIImage above an UIImageView, possible? example code?

Is it possible to set an image over an other image,
respectively to overlay an image above an UIImage.
I give some code:
Headerfile:
#property (nonatomic,assign)UIImageView* imageView;
Implementationfile
UIImage *overlayImage = [UIImage imageNamed:#"lamp.png"];
The "imageView.image" has got an image and above that I will have this lamp, but later on it has to be possible to move it.
I searched some methods, but all methods gave me warnings.
Could you help me how to manage it? And is Core Animation an alternative to handle that?
Just add it as a subview. UIImageView is a UIView like any other.
UIImage *overlayImage = [UIImage imageNamed:#"lamp.png"];
UIImageView *overlayImageView = [[UIImageView alloc] initWithImage:overlayImage];
[self.imageView addSubview:overlayImageView];
You should use another UIImageView. A UIImage doesn't refer to an actual view in the interface, it's used as a reference to an image to be reused in code.
UIImageView* lampImageView= [[UIImageView alloc] initWithImage:overlayImage];
This way you can move it around anywhere over the first image view.