Case 3: Presentation of high definition panoramic images

In this exercise the intention was to slowly pan one of 4 high definition panoramic images from the left to the right across two 30" Apple displays. Each panoramic image was a 16000x2000 pixel image, at any one time perhaps 1/3 of the panoramic image would be visible across the dual displays, it would take perhaps a minute for the panning to complete 360 degrees and then switch to the next panoramic image. Total display dimensions: 5120 pixels by 1600.

Each display is driven by it's own Quartz Composer composition, this is due to the limitation that fullscreen of a QC composition only affects one display, a common limitation for full screen mode for Mac applications but a limitation not imposed by the graphics/window system! The content is synchronised (the positions of the sprites on each display) by performing all timing and positioning with respect to the system clock. Quartz composer files for each screen are provided here: boolardy1.qtz and boolardy2.qtz (actual panoramic media files not included).

• Quartz Composer seems to subsample/degrade the image quality of these large images. The onscreen quality was close to 1:1 and yet the images were significantly lower quality than the images at the same scale in PhotoShop say. [This has subsequently bee relaxed in QC version 3 and Leopard, the textures (it seems) are subsampled down to the maximum texture size that can be handled by the graphics card].

• Why isn't "full screen" usually implemented as real full screen, that is, across all displays?

The following is an example of one of the panoramic images, the image below is a 1/20 scaled down version, clicking on the following image will show a 1/8 scaled down version.

Photos

Hardware

Mac G5 (PPC) and Quadro FX4500 graphics card (2 x dual link DVI), 2 Apple 30" displays.