Author |
Message |
Giorgio Bogoni
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, July 09, 2001 - 2:03 pm: | |
As long as we want to share anaglyphic images over the Internet we need an efficient compression method. GIF format works fine but allows only 256-colors images (it can be used for CG). PNG format works fine IF we've got a 256-colors image. JPEG format can be used only setting a low-compression level because it works in the color space and anaglyphic stereo images too. Does anybody knows about a compression method working in separate RGB channels? As far as I can understand we need a compressor super-imposing 2 compressed channels: compressed R-channel and compressed GB-channel. Any suggestion? |
Anonymous
Rating: N/A Votes: 0 (Vote!) | Posted on Thursday, July 12, 2001 - 1:18 am: | |
i'm using an LCD monitor on my PC & wonder if there's any D3D anaglyph driver for my geforce MX board. i love my D3D driving games! |
Giorgio Bogoni
Rating: N/A Votes: 0 (Vote!) | Posted on Thursday, July 12, 2001 - 8:04 am: | |
Maybe GLDirect or eyescream light could work (none of them works on my ATI mobility rage chipset but I aspect them to work on a NVIDIA one) Let me know, Giorgio |
Brightland
Rating: N/A Votes: 0 (Vote!) | Posted on Thursday, July 12, 2001 - 7:23 pm: | |
A simple custom format based on JPEG'ing r,g, and b separately could be quickly and trivially implemented. The drawback is a custom control would be needed (unless it is done in JAVA, etc.) John |
Giorgio Bogoni
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, July 15, 2001 - 8:56 pm: | |
John, my goal was to share R/C anagyph in HTML pages minimazing loading time. As far as you know is there any way programming HTML to load the GB compressed image and THEN (IN THE SAME PLACE) the R compressed one with an alpha channel so that both images are visible superimposed? Thanks |
Brightland
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, July 16, 2001 - 5:48 pm: | |
Giogio, It's probably possible using something like Flash, and certainly possible using Java. Steps: 1. Take an RGB R/C image and split into 3 grayscale JPEGs. Save on web server. 2. Create Flash/Java code to grab and recombine the 3 JPEGs. 3. Add a zoom/scale option, etc. John |
Brightland
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, July 16, 2001 - 5:53 pm: | |
Giorgio, One more option that may yield smaller overall size: 1. Save the red channel as grayscale JPEG. 2. Remove the red channel (set to black) and save GB channels as RGB JPEG. 3. Save both files on webserver. 4. In Flash/Java code, load red (grayscale) and cyan (as RGB) JPEGS. Copy the red channel into the RGB cyan image and display. John |
Giorgio Bogoni
Rating: N/A Votes: 0 (Vote!) | Posted on Tuesday, July 24, 2001 - 10:42 pm: | |
John, I'm not able to write the necessary JAVA or FLASH code but I've tested your idea using a real-life picture. I've looked at a 5 quality jpg anaglyphic image (80 kb) and at a 3+3 quality image (obtained joining a 3 quality R image and a 3 quality GB image) (20+40=60 kb). Well, as I aspected the first one shows a little more ghosting (jpg compression mixs up colors) but the second one is much more "pixeled" (high compression creates large pixels). Considering the loading time of the java applet we can say the two images need the same time to be loaded ... well, I'm not sure which one is better (stereo-speaking the second one but the first one is more detailed). Has anybody tried something like this? Giorgio. |
Brightland
Rating: N/A Votes: 0 (Vote!) | Posted on Thursday, July 26, 2001 - 7:56 am: | |
Giorgio, I suspect a FLASH or Director based solution will load very quickly. The ideal solution is to use wavelet compression (higher compression, no "block effects"), which will be available in JPEG2000... In the meantime, a FLASH/Director/JAVA version should work fine (the applet should only take time the first load, after that it should be cached). Regards, John |
Giorgio Bogoni
Rating: N/A Votes: 0 (Vote!) | Posted on Thursday, July 26, 2001 - 9:49 am: | |
Thanks John. Let us know if (when available) wavelet compression works fine. Giorgio. |