- (UIImage*)imageByScalingAndCroppingForSize:(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; // scale to fit height
else
scaleFactor = heightFactor; // scale to fit width
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;
}
}
UIGraphicsBeginImageContext(targetSize); // this will crop
CGRect thumbnailRect = CGRectZero;
thumbnailRect.origin = thumbnailPoint;
thumbnailRect.size.width = scaledWidth;
thumbnailRect.size.height = scaledHeight;
[sourceImage drawInRect:thumbnailRect];
newImage = UIGraphicsGetImageFromCurrentImageContext();
if(newImage == nil)
NSLog(@"could not scale image");
//pop the context to get back to the default
UIGraphicsEndImageContext();
return newImage;
}
+ (UIImage *)compressImageQuality:(UIImage *)image toByte:(NSInteger)maxLength{
CGFloat compression = 1;
NSData *data = UIImageJPEGRepresentation(image, compression);
while (data.length > maxLength && compression > 0.000001) {
if (data.length*1.0/maxLength>=2) {
CGFloat scale = data.length/maxLength;
UIImage *cureeimage = [UIImage imageWithData:data];
CGSize scalesize = CGSizeMake(cureeimage.size.width/scale, cureeimage.size.height/scale);
UIImage *sizeimage = [cureeimage imageByScalingAndCroppingForSize:scalesize ];
compression =1;
image = sizeimage;
}else if (data.length*1.0/maxLength>=1.5){
compression /=1.5;
}else{
compression /=1.2;
}
data = UIImageJPEGRepresentation(image, compression); // When compression less than a value, this code dose not work
}
UIImage *resultImage = [UIImage imageWithData:data];
if (resultImage!=nil) {
return resultImage;
}else{
return image;
}
return resultImage;
}