CODEWITHSUNDEEP
iosiphoneobjective-cuiimageviewuiimage
user3117509
user3117509

Reputation: 833

UIImage distorted when using it for UIImageView

I have taken a photo, and then I'm initializing a UIImageView object with this photo. The only problem is, when I take the photo, the photo is being taken using the full iPhone screen (portrait).

The UIImageView that is being initialized with this photo is only set to take up the top 50% of the iphone's screen. So you can imagine the image looks distorted.

I have been able to make it look a lot better by using the following code:

UIImageView *halfView = [[UIImageView alloc]initWithImage:image];

[self.view addSubview:halfView];

halfView.frame = CGRectMake(0, 0, self.view.bounds.size.width, self.view.frame.size.height/2);

halfView.contentMode = UIViewContentModeScaleAspectFill;

The only problem is, the final UIImageView called "halfView" is still slightly distorted.

I have a feeling that this is impossible to fix, because the original photo is being taken with the full iphone screen and can never perfectly scale to fit a UIImageView that only takes up the top 50% of the iphone screen.

I was basically trying to copy the frontback app. Here is what it looks like when you are taking the original image in their app:

enter image description here

This is what my app's screen looks like when you are taking the picture:

enter image description here

And then right after you take the picture, my app's screen changes to look like the frontback screen and takes the picture you just took and places it in the top half and tries to scale it.

I hope that makes sense. I know it is a long question, but I just really wanted to let the user use the full screen while taking the photo and then just scale it to half the screen.

Am I going about this all wrong? Am I crazy to think I could ever properly scale the image to half the screen when it was originally captured as a "full screen" image?

Thanks for the help.

Upvotes: 0

Views: 2272

Answers (3)

Jim Tierney
Jim Tierney

Reputation: 4105

You mention the image takes up the full size of the screen. If it's to display the UIImageView taking up half the screen, then you'll need to add this code to clip the frame

halfView.clipToBounds = YES;

Despite making the size of the imageview half the screen, the actual image will show outside the boundaries of the imageview if it's original size is bigger with the aspectFit property. clipToBounds will fix this.

I hope this is what you're looking for. Thanks, Jim.

Upvotes: 0

Prashant Nikam
Prashant Nikam

Reputation: 2251

Try this function, pass your UIImage in this function along with the new size, in turn it will return you the UIImage with size specified by you.

- (UIImage *)imageWithImage:(UIImage *)image scaledToSize:(CGSize)newSize {
    UIGraphicsBeginImageContextWithOptions(newSize, NO, 0.0);
    [image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}

I guess this is what you want. Hope this helps.

Upvotes: 1

Gad
Gad

Reputation: 2877

For the sake of argument let's say your captured image size is 640x1136 (twice the size of an iPhone 5 screen) and you are trying to display it in a UIImageView with of size 320x284 (half the size of an iPhone 5 screen). As you can already see from these dimensions the captured image's width is smaller than its height whereas the UIImageView's width is larger than its height - the proportions are different.

Therefore, scaling the captured image to fit the UIImageView's width (scale by 0.5) means the captured image will be of size 320x568 - its height is larger than the UIImageView's height. Scaling the captured image to fit the UIImageView's height (scale by 0.25) means the captured image will be of size 160x284 - its width is smaller the the UIImageView's width.

The image can't scale exactly like you want it to scale. However, you can use UIViewContentModeScaleAspectFill to fill the entire UIImageView but lose some of the image (image's height is too big to fit). You can also choose to use UIViewContentModeScaleAspectFit which will show the entire image but will leave some space on the sides (image's width is too small).

Another option you have is to actually capture the image in the proportions of your UIImageView in the first place but that means you won't be able to capture a full screen image.

Upvotes: 1

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