How can I make the large image into small with as good quality as the original image?

Question

I am using imagview with size of 80X80 to display large image (1024 X 780).

While placing the large image into the imageview, the image looks squeezed, compressed something not like the quality one.

My question is, how can I make the large image into small with as good quality as the original image ?

score 1 · Answer 1 · answered Jul 22 '11 at 07:22

1

In the image view, please make the imageview.mode as centre not scale to fit or any other. I believe this would put ur any scaled image at finest quality in ur 80x80 dimension.

answered Jul 22 '11 at 07:22

SABARISH CHOKKALINGOM

111
5

score 1 · Answer 2 · answered Jul 22 '11 at 07:24

In this case, you should do proper Scaling of the Image that u want to show in the ImageView

- (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize 
{
    UIImage *sourceImage = chosenImage;
    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*1;
        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;
        }
    }


    UIGraphicsBeginImageContext(targetSize);

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

    [sourceImage drawInRect:thumbnailRect];

    newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage ;
}

than q surya this coding is usefull my concept – Durga Jul 22 '11 at 07:34 — Durga, Jul 22 '11 at 07:34

score 1 · Answer 3 · edited May 23 '17 at 12:04

1

[imageView setContentMode:UIViewContentModeScaleAspectFill];

You should however consider resizing the image and saving it on the disk if you want to use it more then once. To resize the image:

The simplest way to resize an UIImage?

UIImage resize (Scale proportion)

UIImage: Resize, then Crop

etc..

edited May 23 '17 at 12:04

Community

1
1

answered Jul 22 '11 at 07:25

alex-i

5,406
2
36
56

than q surya this coding is usefull my concept – Durga Jul 22 '11 at 07:35

score 0 · Answer 4 · answered Mar 04 '13 at 13:29

0

you can set image mode [imageView setContentMode:UIViewContentModeScaleAspectFill]; imageView.autoresizingMask = ( UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight ); [imageView setClipsToBounds:YES];

answered Mar 04 '13 at 13:29

Banker Mittal

1,918
14
26

score 0 · Answer 5 · answered Jul 22 '11 at 07:20

0

Going from 1034x780 into 80x80 is virtually impossible to keep the quality, as there isn't enough space to capture all the details.

You can try to scale it:

+ (UIImage*)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize;
{
    UIGraphicsBeginImageContext( newSize );
    [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newImage;
}

answered Jul 22 '11 at 07:20

Cyprian

9,423
4
39
73

This works, but in iOS5.0.1 its causing a memory leak. Is there an alternative approach? http://stackoverflow.com/questions/8236837/memory-leak-drawinrect-on-ios5-0-1 – David Nov 23 '11 at 14:22

How can I make the large image into small with as good quality as the original image?

5 Answers5