I need to crop a UIImage, taken with the device camera, so that it fits inside another UIImage, which represents a frame (with rounded borders and so on). Check the image below:
Using Aspect Fill
Using Aspect Fit
So, what I need is to remove the image excess that is out of the frame bounds.
I tried using UIBezierPath, CGImageRef and other methods that I Googled but I'm not finding a solution for this.
In Interface Builder, use the following configuration:
There are two important settings, namely:
Mode: Aspect Fill
Clip Subviews
It can also be done programmatically:
[imageView setContentMode:UIViewContentModeScaleAspectFill];
[imageView setClipsToBounds:YES];
This will correctly fill the view with the image, keep its aspect ratio and hide what doesn't fit.
make a IBOutlet in your controller.
#property (retain)IBOutlet UIImageView* imageView;
and in -(void) viewDidLoad set
imageView.layer.masksToBounds = YES;
In interface Builder, access the Mode menu inside of the detail pane (the fourth one) and choose the right one for your UIImageView (I guess "center" or "aspect fit").
OLD ANSWER:
You can use the contentGravity property of CALayer to make it work
A constant that specifies how the layer's contents are positioned or scaled within its bounds.
#property(copy) NSString *contentsGravity
Use an UIImageView and do
imageView.contentMode = UIViewContentModeScaleAspectFit;
Related
I am trying to export an image from a UIView that contains a UIImage view and some labels. I am not sure I am going about this the right way. I want to export everything in the view and maintain the layout. I want to export at 1536 x 2048.
I am using the following code with renderInContext to grab an image of the main view (UIView). Kind of works, but the layout gets messed up, basically the layout changes and the labels do not scale properly. Is renderInContext the right way to go for something like this? Is there a better way?
you can download the whole project here: http://tinyurl.com/7qvhqtp
UIGraphicsBeginImageContext(CGSizeMake(1536, 2048));
viewOutput.frame = CGRectMake(0, 0, 1536, 2048);
[[viewOutput layer] renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(image,nil,nil,nil);
This is the code I use to save the current UIView as an image. The layout gets saved perfectly.
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, self.view.opaque, 0.0);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
I'm not 100% sure, but there might be some issues with UIGraphicsBeginImageContext vs UIGraphicsBeginImageContextWithOptions.
On the other hand the problem might be in your view's subview's autoresizing mask if your view has the autoresizesSubviews set to YES. I'd try to disable it if you do not have the support for rotations or at least before changing your view's frame.
The only thing you did to get a bigger image was to change the frame but the labels did not have the correct autoresize masks nor did their font size change. You can clearly see this in the "after running code" image that the label did neither move nor change size.
First, If you wan the label to change its frame when the superview's frame changes (are the labels subviews of the image? If not you may need to calculate their new frames yourself) then you should give it a suitable auroresizing mask. In your case you would want it to have a fixed distance to the bottom of the screen and a flexible distance to the top. You would also want the distances to the left and right to be fixed so that the width can be flexible.
This only leaves you with the font size problem. You should calculate the scale factor (how many times bigger everything gets) and multiply the current font size with that scale factor.
I have a UIView has some labels and buttons on it.
Next I also have a image which has a square area that is transparent, now
if I create a UIImageView and add this image which has transparent regions I am not able to see the background view (which has buttons and labels) through this transparent image.
If I play with the alpha value that doesn't work as intended which is to see the transparent regions exactly as it would have appeared on the UIView which has the labels and buttons.
UIImage* image = [UIImage imageNamed:#"TI1.jpg"];
UIImageView* imageView = [[UIImageView alloc] initWithImage:image];
[self.view addSubview:imageView];
Also I would be interested to know if there is other way to achieve what I am trying to achieve.
Basically I want to highlight a certain area of the view which has buttons/labels and make the rest of the area greyed out. My idea was to have this UIImageView with transparent regions in image to achieve that.
Thanks
Ankur
Try setting imageView.opaque = NO;
UIImageView inherits from UIView. According to that class's docs:
This property provides a hint to the drawing system as to how it
should treat the view. If set to YES, the drawing system treats the
view as fully opaque, which allows the drawing system to optimize some
drawing operations and improve performance. If set to NO, the drawing
system composites the view normally with other content. The default
value of this property is YES.
Also, not sure that JPG even supports transparency, so try exporting the image as a PNG to ensure you get the results you're looking for.
How does one set a UIImageview's image to the actual image size rather than filling the view with the image and thus stretching the image(if the image is smaller than the UIImageView's size)
You want to adjust the contentMode property. I suspect to UIViewContentModeCenter.
Create the UIImageView like this:
UIImageView *aImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"yourImage.png"]];
So the ImageView has the size of the image.
I hope my answer helps you.
Note that if you're in IB or a Storyboard, click on the Attributes inspector tab after selecting your imageview, look down in the View section (under ImageView) and where it says "mode", change the selection from "scale to fill" (the default) to "center"
I think this is basically the IB equivalent of Tommy's answer, which does the same only programmatically.
In my view I have a picture.. The picture has a 3:2 scale and is huge, resolution wise.
I'm having a lot of trouble initializing a UIImage with the image to the original size and then zooming out of the UIImageView so that the entire image is visible within the scrollview.
The program stays only in the portrait orientation.
And no, please don't say to just use UIWebView. UIWebView doesn't let me set the content size during view load...instead, it just zooms out of the image by some arbitrary scale and I couldn't figure out a way to adjust the scale value (I don't think it's possible).
Thanks for any responses! I really appreciate them :D
Here's an example of placing an image that responds to pinch-to-zoom. Basically, you place the UIImageView in a UIScrollView and change some settings.
UIImageView *myImage;
UIScrollView *myScroll;
-(void)viewDidLoad{
myImage = [[UIImageView alloc] initWithFrame:CGRectMake(0,0,360,450)];
[myImage setImage:[UIImage imageNamed:#"coolpic.png"]];
myImage.contentMode = UIViewContentModeScaleAspectFit;
[myScroll addSubview:myImage];
[myScroll setContentSize:CGSizeMake(myImage.frame.size.width, myImage.frame.size.height)];
[myScroll setMinimumZoomScale:1.0];
[myScroll setMaximumZoomScale:4.0];
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{
return myImage;
}
Of course, set all your delegates and IB hooks properly.
Edit: I just reread your question. The portion of the example that answers your question is the frame specification of the UIImageView and its contentMode setting.
You almost certainly don't want to load your 'huge, resolution wise' image all at once on load regardless of it's scale. I'd suggest checking out some of Apple's sample code on this stuff (starting with ScrollViewSuite would be good, I'd say).
There was also a recent video released from WWDC where they implement this sort of thing live (they have more of a photo viewing app, but you could pretty easily do what they show with just one image too) so take a look for that too.
Go to the attributes tab of the UIImageView. Select "aspect to fill" or "aspect to fit". If you use "aspect to fill", you might not show the whole image. I just use "aspect to fit", and make the background black.
set a UIImageView.image property to a UIImage is unable add the image to the view,however if i set the imageview frame property,it works.can anyone tell me how it's happen?
and what will happen when i apply the UIImage instance method[drawInRect:] redraw the image frame which is larger than the view frame?i have tried but nothing happen,and what is this function doing actual?
Generally, how it works is, you add an Image to a UIImageView and then add the UIImageView to a UIView to display it on the screen. You can do this programmatically, or using Interface Builder. Optionally, you can create a CGRect (based on a frame, if you like), use this as the bounds for the UIImageView (or you can frame the UIView). There are several ways to do what you want to do.
It's hard to tell without seeing your code. It could be a number of things. You could be inserting the view with the image behind the currentView? You may not be retaining the UIImageView. We can't read minds here necessarily, (sometimes we do). But you'll need to be more helpful if you want a solid answer.
Or just take a look at this:
UIImageView Docs