What exactly is Matrox up to .... get the <facts>

[rubank]

Maggi,

I have to agree with Icy and Womby.

If you do the operation you discribed using Photoshop 6 and set JPEG quality to "maximum" the result will be a 0/0/0 rgb image.
You can verify it by "adjust/equalize" whereby Photoshop answers that there is only one brightness value in the image.

If you on the other hand use Corel Photopaint 10, the best JPEG setting will not result in a lossless compression. You just have to magnify the image to see the brown pixels.

This is of course only interesting from a theoretical standpoint, for all practical reasons a mildly compressed JPEG image is indistinguishable from the uncompressed image on a monitor.

rubank

[mute]

oh and what is a matrox gc2000 ?

saw something in the new bios , there's something about a marvel g550 eTV
and a g550 engineering board
and g550 prototype
and matrox dual condor

[orangejulius]

You're right.

PBIOSWIN.EXE contains:
00067488: Matrox Marvel G550 eTV
000674B8: G550 Engineering Board
000674D0: G550 prototype
00067694: Matrox CG2000
00067760: Matrox Dual Condor
00067910: Digital First Millennium G450 32S

PROGBIOS.EXE contains:
0004CB70: :filetype TOUCAN
0004CDDA: :filetype CONDOR

[[GDI]Raptor]

Dual Condor... Whats that..?? I you serch throug the latest driver from Matrox... What do yuo find??

[KngtRider]

cg2000 could mean condor g2000

if there is a dual, would YOU BUY IT THOUGH?

all the multi chip solutions didnt work well from all manufs for soho use

re g550 prototype - it could have been one with the full tl engine avalible to all apps for matrox to develop the tl on

g550 etv - they said no more low end capture cards

[mute]

ohh yeah now i remember the cg2000
if you still haven't seen what it is orangejulius posted the url in a previous post

wasn't the g450 codenamed condor ? dual could mean dualhead
i'd have to see in previous bios releases

[Maggi]

Hi Guys,

seriously, I didn't know there existed a lossless JPEG version and even the highest setting in Photoshop 6 is, unlike Rubank stated, not lossless.
I guess it heavily depends on the pictures contents, because my example resulted in a difference picture that contains 116 unique colors.

Uncompressed it is 1.440.056 bytes in size, in Photoshop JPEG 12/12 baseline optimized it is 336.560 bytes.
I stored the difference as GIF, because it has only 116 colors and hence GIF is smallest lossless format. The exagaration of that difference picture was done by raising gamma to 9 and it's also in GIF for above reasons.

I don't have any webspace, hence I'll attach the pictures one after another.

Here's the original, compressed quite heavily to match the max file size of this forum

[Maggi]

unfortunately I had to convert the difference pictures to JPG, because the GIFs were 318KB each ... doh !

I also had to lower the gamma, because teh resulting JPG was about 1.2MB in 12/12 and still +100KB in 1/1 ...

So here now the black looking difference picture without gamma correction

[Maggi]

Finally the difference with gamma set to 5, but be aware that the use of 5/5 as quality level lowered the picture detail.

[omegaRED]

Toucan is the codename for the G400, and Condor for the G450, dual Condor is obviously G450 DualHead ...

[KngtRider]

hes right, i rmeber running some g400 info utiltily and it said toucan rev whatever

[Wombat]

How do you know the GIF was lossless? Not critisizing, just want to know for my own understanding.

[IcedEarth]

Originally posted by omegaRED
Toucan is the codename for the G400, and Condor for the G450, dual Condor is obviously G450 DualHead ...

All G450's are dualhead by default so it's kinda weird to make a difference between a Condor and a dual Condor then; right?

[rubank]

Deleted to save bandwidth

[Maggi]

Originally posted by Wombat
How do you know the GIF was lossless? Not critisizing, just want to know for my own understanding.

Hi Wombat,

afaik is GIF able to store 256 unique colors (8 bit out of 24) and all my tests indicate that they are stored lossless. Since the difference picture above contained 116 colors (image > mode > indexed color = "exact"), GIF is able to store it as it is, without having to dither and/or round down.




Hi Rubank,

I guess it depends on the actual picture contents, ie. in my case I scanned the pic on my own in very high resolution so that even the filmgrain was reproduced properly ...
I have no clue about your example, but it seems that there's not too much detail anyways and hence it might very well be the case that JPEG can store it lossless. Especially if your started of with a JPEG and saved it to TIFF or BMP, you wouldn't have any differences.
Just do a scan on your own and compare again.

Another aspect could be that to my knowlegde the JPEG fileformat use YUV colorspace while BMP uses RGB and TIFF is sort of free to use any kind of color channel. Most likely the according colorspace conversion already changes the picture, depending on the actually used colors.

Cheers,
Maggi