如何在不减小ios的高度和宽度的情况下减小图像的大小？

Question

Please guide me. how to reduce the size of image with out reducing height and width in ios?

I will take a photo through device camera. the size around 250kb. Now I want to reduce 100KB without resizing the height and width.

Is it possible to do it?

Please Share your views.

Answer 1

Convert the jpg image to jpeg will reduce size. Try this.

[UIImage imageWithData:UIImageJPEGRepresentation(img, 0.01f)];

Answer 2

I generally use this function for compression of images on iOS that I found on this answer .

+ (NSData*)imageDataWithCGImage:(CGImageRef)CGimage UTType:(const CFStringRef)imageUTType desiredCompressionQuality:(CGFloat)desiredCompressionQuality
{
    NSData* result = nil;

    CFMutableDataRef destinationData = CFDataCreateMutable(kCFAllocatorDefault, 0);
    CGImageDestinationRef destinationRef = CGImageDestinationCreateWithData(destinationData, imageUTType, 1, NULL);
    CGImageDestinationSetProperties(destinationRef, (CFDictionaryRef)[NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithFloat:desiredCompressionQuality], (NSString*)kCGImageDestinationLossyCompressionQuality, nil]);
    if (destinationRef != NULL)
    {
        CGImageDestinationAddImage(destinationRef, CGimage, NULL);

        if (CGImageDestinationFinalize(destinationRef))
        {
            result = [NSData dataWithData:(NSData*)destinationData];
        }
    }
    if (destinationData)
    {
        CFRelease(destinationData);
    }
    if (destinationRef)
    {
        CFRelease(destinationRef);
    }
    return result;
}

The image type can be kUTTypePNG, but the quality parameter most likely will not work. It also can be kUTTypeJPEG2000 for your needs.