Save img with UIImagePickerController - iphone

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

Image returns from camera has 1200*1600 pixal resolution and one pixel is represented by 4 byte. only option to decrease the memory sizeis the resize Image and then compress image in to JPEG or PNG. You can use below method to resize the Image
+ (UIImage*)imageWithImage:(UIImage*)image
scaledToSize:(CGSize)newSize;
{
UIGraphicsBeginImageContext( newSize );
[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
...

Answer 2

You can decrease the size of the image by decresing its size
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
[picker dismissModalViewControllerAnimated:YES];
NSData *imageData = UIImageJPEGRepresentation([info objectForKey:#"UIImagePickerControllerOriginalImage"],.5);
UIImage *image = [UIImage imageWithData:imageData];
CGSize size=CGSizeMake(150,150);
UIGraphicsBeginImageContext(size);
[image drawInRect:CGRectMake(0, 0, size.width, size.height)];
UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
imgView.image =scaledImage; // setting this image imgView"Its a image view" on my view

Answer 3

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! =)

Answer 4

Well, the easiest way is to save it as JPEG and reduce the quality. You set it to 1.0, which results in 3.2 MB, but in my experience a JPEG quality of 0.3 is sufficient for most tasks - you can even read the text in a photo of a newspaper article written with 0.3 quality. The size then is about 700K.
For resizing you should have a look at this excellent article:
http://vocaro.com/trevor/blog/2009/10/12/resize-a-uiimage-the-right-way/