Question

I am using UIImagePickerController for bring images from the photo library,

i found this method for saving the uiimage as png or jpeg:

- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];

    // Create paths to output images
    NSString  *pngPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Test.png"];
    NSString  *jpgPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Test.jpg"];

    // Write a UIImage to JPEG with minimum compression (best quality)
    // The value 'image' must be a UIImage object
    // The value '1.0' represents image compression quality as value from 0.0 to 1.0
    [UIImageJPEGRepresentation(image, 1.0) writeToFile:jpgPath atomically:YES];

    // Write image to PNG
    [UIImagePNGRepresentation(<#UIImage *image#>) writeToFile:jpgPath atomically:YES];

    // Let's check to see if files were successfully written...

    // Create file manager
    NSError *error;
    NSFileManager *fileMgr = [NSFileManager defaultManager];

    // Point to Document directory
    NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];

    // Write out the contents of home directory to console
    NSLog(@"Documents directory: %@", [fileMgr contentsOfDirectoryAtPath:documentsDirectory error:&error]);

    [picker release];
}

the problem is that the file in png is 6.4 mb and in jpeg 3.2 mb, there is a way for saving the image file in smaller size then this?

Answer 1

you could resize image and save image in smaller size.

Here is an example of method for resizing image:

- (void)setThumbnailFromImage:(UIImage *)image {
    CGSize origImageSize = [image size];

    CGRect newRect;
    newRect.origin = CGPointZero;
    newRect.size = CGSizeMake(40, 40);

    // how do we scale the image?
    float ratio = MAX(newRect.size.width/origImageSize.width,
                      newRect.size.height/origImageSize.height);

    // create a bitmap image context
    UIGraphicsBeginImageContext(newRect.size);

    // Round the corners
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:newRect
                                                    cornerRadius:5.0];
    [path addClip];

    // into what rectangle shall I composite the image?
    CGRect projectRect;
    projectRect.size.width = ratio * origImageSize.width;
    projectRect.size.height = ratio * origImageSize.height;
    projectRect.origin.x = (newRect.size.width - projectRect.size.width) / 2.0;
    projectRect.origin.y = (newRect.size.height - projectRect.size.height) / 2.0;

    // draw the image on it
    [image drawInRect:projectRect];

    // get the image from the image context, retain it as our thumbnail
    UIImage *small = UIGraphicsGetImageFromCurrentImageContext();
    [self setThumbnail:small];

    // cleanup image contex resources, we're done
    UIGraphicsEndImageContext();
}

Hope this will help you! =)