[Synotic]

OK, here's my objective.. I want to take a screenshot of a section of the screen and then save it as a JPEG. Here's what I have...

NSBitmapImageRep *grabbedImage = [[NSBitmapImageRep alloc] initWithFocusedViewRect:NSMakeRect(0, 534, 386, 298)];

NSData *grabbedImageData = [grabbedImage representationUsingType:NSJPEGFileType properties:[NSDictionary dictionaryWithObject:[NSNumber numberWithFloat:0.0f] forKey:@"NSImageCompressionFactor"]];

[[NSFileManager defaultManager] createFileAtPath: [[NSString stringWithString: @"~/Desktop/newlycreatefile.jpg"] stringByExpandingTildeInPath] contents: grabbedImageData attributes: [NSDictionary dictionaryWithObjectsAndKeys:@""]];

In this first line I am making a NSBitmapImageRep by giving it the coordinates of the screen I want to take a picture of. Then I am turning it into an NSData which I then use as the contents of the file I create in the third line. However this doesn't work... It compiles fine... I hit the button.. no warnings... On the desktop there is newlycreatedfile.jpg, however the Finder reports it as being 0 KB. Now dragging it on Chimera tells me it can't be displayed due to errors. And OmniWeb gives a big clue:

Cannot Load Address

Not a JPEG file: starts with 0xff 0xd9

Which leads me to believe that I am generating a TIFF file (or at least something that identifies itself as a TIFF file but has no content). And sure enough, changing the file extension to .tiff and dragging it onto OmniWeb doesn't show this error (though it doesn't show anything at all... sense it is zero bytes).

So what can I do? Am I approaching this wrong? How can I make it really a JPEG and have it actually have the data I put in there. Sorry for all the questions but I really need to get this working! Thanks

[Angus_D]

You can't do that, I don't think. "FocusedViewRect" means just that - a rect in the view you are currently focused in (with lockFocus). You'll probably have to do something exciting with the screen base address pointer which you can get from CoreGraphics, or use some Carbon fun.

[absmiths]

Originally posted by Synotic:

Not a JPEG file: starts with 0xff 0xd9

I think it's interesting that a zero-byte file apparently contains at least the two bytes mentioned above. Technically, a zero-byte file is not in any format, tiff, gif, jpeg, doc or otherwise.

Kind of makes you wonder where OmniWeb is getting those bytes?

[Gul Banana]

'twasn't 0 bytes; the finder said 0 KB, which is accurate to within 1024 bytes.