CGRect image sizing question

Question

I'm using CGRect to display an image. I'd like the CGRect to use the width and height of the image without me specifying it.

can this:

CGRectMake(0.0f, 40.0f, 480.0f, 280.0f);

become this:

CGRectMake(0.0f, 40.0f, myImage.width, myImage.height);

some images get distorted when I specify the parameters.

here's the code:

CGRect myImageRect = CGRectMake(0.0f, 40.0f, 480.0f, 280.0f);
UIImageView *myImage = [[UIImageView alloc] initWithFrame:myImageRect];
[myImage setImage:[UIImage imageNamed:recipe.img]];

thanks for any help.

Answer 1

This category on UIImage might be helpful.

Use it like this: aImage =[aImage imageByScalingProportionallyToSize: myImageRect]

@implementation UIImage (Extras)

- (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize {

    UIImage *sourceImage = self;
    UIImage *newImage = nil;

    CGSize imageSize = sourceImage.size;
    CGFloat width = imageSize.width;
    CGFloat height = imageSize.height;

    CGFloat targetWidth = targetSize.width;
    CGFloat targetHeight = targetSize.height;

    CGFloat scaleFactor = 0.0;
    CGFloat scaledWidth = targetWidth;
    CGFloat scaledHeight = targetHeight;

    CGPoint thumbnailPoint = CGPointMake(0.0,0.0);

    if (CGSizeEqualToSize(imageSize, targetSize) == NO) {

        CGFloat widthFactor = targetWidth / width;
        CGFloat heightFactor = targetHeight / height;

        if (widthFactor < heightFactor) 
            scaleFactor = widthFactor;
        else
            scaleFactor = heightFactor;

        scaledWidth  = width * scaleFactor;
        scaledHeight = height * scaleFactor;

        // center the image

//        if (widthFactor < heightFactor) {
//          thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5; 
//        } else if (widthFactor > heightFactor) {
//          thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
//        }

        //thumbnailPoint.x
    }


    // this is actually the interesting part:

    UIGraphicsBeginImageContext(targetSize);

    CGRect thumbnailRect = CGRectZero;
    thumbnailRect.origin = thumbnailPoint;
    thumbnailRect.size.width  = scaledWidth;
    thumbnailRect.size.height = scaledHeight;

    [sourceImage drawInRect:thumbnailRect];

    newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    if(newImage == nil) NSLog(@"could not scale image");


    return newImage ;
}

@end;

Answer 2

Once you have a UIImage, you can find it's size by looking at it's size property:

UIImage * image = [UIImage imageNamed:recipe.img];
CGRect rect = CGRectMake(0.0f, 40.0f, image.size.width, image.size.height);

UIImageView * imageView = [[UIImageView alloc] initWithFrame:rect];
[imageView setImage:image];