Download an Image and Save it as PNG or JPEG in iPhone SDK

[url]http://blog.objectgraph.com/index.php/2010/04/05/download-an-image-and-save-it-as-png-or-jpeg-in-iphone-sdk/
[/url]
Here is a quick example to save an image as JPEG or PNG. In this tutorial, I’m getting the image from the Internet then I’m saving it as JPEG and PNG.

Key points:

    * NSData to retrieve the image from the URL
    * NSDocumentDirectory to find Document folder’s Path
    * UIImagePNGRepresentation to save it as PNG
    * UIImageJPEGRepresentation to save it as JPEG

	NSLog(@"Downloading...");
	// Get an image from the URL below
	UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://www.objectgraph.com/images/og_logo.png"]]];
 
	NSLog(@"%f,%f",image.size.width,image.size.height);
 
	// Let's save the file into Document folder.
	// You can also change this to your desktop for testing. (e.g. /Users/kiichi/Desktop/)
	// NSString *deskTopDir = @"/Users/kiichi/Desktop";
 
	NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
 
	// If you go to the folder below, you will find those pictures
	NSLog(@"%@",docDir);
 
	NSLog(@"saving png");
	NSString *pngFilePath = [NSString stringWithFormat:@"%@/test.png",docDir];
	NSData *data1 = [NSData dataWithData:UIImagePNGRepresentation(image)];
	[data1 writeToFile:pngFilePath atomically:YES];
 
	NSLog(@"saving jpeg");
	NSString *jpegFilePath = [NSString stringWithFormat:@"%@/test.jpeg",docDir];
	NSData *data2 = [NSData dataWithData:UIImageJPEGRepresentation(image, 1.0f)];//1.0f = 100% quality
	[data2 writeToFile:jpegFilePath atomically:YES];
 
	NSLog(@"saving image done");
 
	[image release];