Proportionally resize UIImage by width

Question

I need to resize UIImage proportionally by width, may be someone have a working code?

For ex.:

Input: Width: 900 Height: 675. Resize to width: 400 width

Result: Width: 400 Height: 300

Please help..

What have you tried? Check out this answer: http://stackoverflow.com/a/537697/1066424 — Aaron Wojnowski, Oct 12 '14 at 20:01

Damian Carrillo · Accepted Answer · 2015-02-05T04:29:37.043

7

Check this blog post out. In particular, these two files:

Maybe this would work for you:

UIImage *image = [UIImage imageNamed:@"SomeImage-900x675"]; // SomeImage-900x675.png
CGFloat targetWidth = 400.0f;

CGFloat scaleFactor = targetWidth / image.size.width;
CGFloat targetHeight = image.size.height * scaleFactor;
CGSize targetSize = CGSizeMake(targetWidth, targetHeight);

UIImage *scaledImage = [image resizedImage:targetSize interpolationQuality:kCGInterpolationHigh];

edited Feb 05 '15 at 04:29

answered Oct 12 '14 at 20:03

Damian Carrillo

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I need height like in Photoshop, when you set new size of image and inputing new weight, it says new height programmatically.. – LightNight Oct 12 '14 at 20:06
so I need a formula.. may be you have it? – LightNight Oct 12 '14 at 20:07
I edited my answer to include an example usage. Hopefully it helps. – Damian Carrillo Oct 12 '14 at 21:00
Wouldn't targetHeight be a factor of size.height, not size.width? – TahoeWolverine Feb 04 '15 at 23:20
@TahoeWolverine Good catch. I've corrected the sample. – Damian Carrillo Feb 05 '15 at 04:30

score 1 · Answer 2 · answered Apr 18 '17 at 04:09

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Couldn't you just set the content mode? to .ScaleAspectFill? Then you can set the UIImageView size to any arbitrary size and the aspect ratio will be preserved.

https://developer.apple.com/reference/uikit/uiviewcontentmode/1622518-scaleaspectfill

answered Apr 18 '17 at 04:09

meds

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Sweet, thanks! I never thought of checking that... worked perfectly. – Drew Apr 13 '18 at 17:44

Proportionally resize UIImage by width

2 Answers2