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best practices for UIImage Resizing Issues When Using Custom Drawing in Objective-C?

👀 Views: 13 đŸ’Ŧ Answers: 1 📅 Created: 2025-06-12
UIImage drawRect CoreGraphics Objective-C

I'm relatively new to this, so bear with me. Hey everyone, I'm running into an issue that's driving me crazy. I'm currently working with an scenario when trying to resize a UIImage in a custom UIView subclass by overriding the `drawRect:` method. Even after resizing the image, the output is blurry and doesn't match the expected dimensions. I'm using iOS 14 and Xcode 12. I've attempted to use `UIGraphicsBeginImageContextWithOptions` to create a new context for drawing, but the resulting image quality remains poor. Here's the code snippet I'm using: ```objective-c - (void)drawRect:(CGRect)rect { UIImage *originalImage = [UIImage imageNamed:@"example.png"]; CGRect imageRect = CGRectMake(0, 0, rect.size.width, rect.size.height); UIGraphicsBeginImageContextWithOptions(imageRect.size, NO, [UIScreen mainScreen].scale); [originalImage drawInRect:imageRect]; UIImage *resizedImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); [resizedImage drawInRect:imageRect]; } ``` I've also tried adjusting the scale parameter in `UIGraphicsBeginImageContextWithOptions`, but it hasn't resolved the blurriness. Additionally, I've ensured that the original image is not being scaled up beyond its resolution. The actual image dimensions are 300x300, and I'm trying to render it at 200x200. Any advice on how to maintain image clarity when resizing or if there's a better approach than using `drawRect:` for this task would be appreciated. I've also looked into using Core Graphics directly, but I'm not sure if that's necessary in this case. The log output doesn't show any errors, but the visual result is disappointing. Thank you! Any suggestions would be helpful.