[Rick1138]

I'm writing a very basic screen saver in Cocoa that displays a static image from a file included in the .app bundle.I had originally planned to use TIFFs and NSImage but each image is approx. 2 MBs,even with compression,an unacceptably large file size,so I would like to use JPEGs with a file size of around 100 KBs each but as everyone knows NSImage doesn't support JPEGs.I would like any advice anyone has on how to read a JPEG from a file and display it in a ScreenSaverView.I'm a beginner programmer so feel free to go into as much detail as you would like.

[michaelb]

Look at using QuickTime's GraphicImporter component. It can read most popular graphics formats, certainly including JPEG.

QuickTIme will handle everything for you - from loading from a filespec (FileRef under X?) to drawing it into whatever drawing port you give it. With QuickTime, you can get a JPEG onto the screen in about 3 lines of code, even in Classic/Carbon.

I can't help you with calling QT with Cocoa though as I haven't been Cocoaized yet.

[Angus_D]

It's not in the Public Beta, but apparantly in later builds you can access Carbon controls from within Cocoa, so QT should work :-)

[tea4u]

Originally posted by Rick1138:
... but as everyone knows NSImage doesn't support JPEGs.

Actually, NSImage can import not only JPEGs but also PNGs, PDFs, PSDs and such, since it now uses QT codec to read image data. You can view what format NSImage accepts by

NSArray *fileTypes = [NSImage imageFileTypes];

The array fileTypes should contain quite a few image format it can import.

[Rick1138]

tea4u,do you know where I can get any more documentation on NSImage and JPEGs?

[tea4u]

Originally posted by Rick1138:
tea4u,do you know where I can get any more documentation on NSImage and JPEGs?

I don't think it's made it in the official documentation yet. Altough I accidentally found it, Cocoa AppKit release note says:

<begin quote>
NSImage via NSBitmapImageRep now uses the QuickTime GraphicsImporter to read additional bitmap image types.
<end quote>

You can find the release note at http://developer.apple.com/techpubs/...es/AppKit.html


[This message has been edited by tea4u (edited 02-14-2001).]

[Rick1138]

Thanks for the info