assuring 16-bit color jpgs.

[Upchurch]

Is there something out there that will determine the color depth of a jpg? Further, is there a product out there that will convert a jpg to 16-bit, if it is not already?

[Meffy]

Hm, hope you won't mind if I ask why... PNG or GIF are more suitable for flat-color images with a limited palette. JPG is best for photographic-type images, where you want to keep continuous color gradations and such.

That said, you could use Photoshop or any similar graphics program to do this. The GIMP is a good free program. http://www.gimp.org/ If you want to do it to batches of images there are good tools for that too.

[Upchurch]

Hm, hope you won't mind if I ask why... PNG or GIF are more suitable for flat-color images with a limited palette. JPG is best for photographic-type images, where you want to keep continuous color gradations and such.Because that's what The Man said it had to be.

This isn't even my responsibility. I have a coworker who would rather have me find things out then to expend the energy herself. Drives me nuts.

[Meffy]

Weird. Righty, what've you got? Software at your command, how many images?

[Upchurch]

Okay, this (http://www.webwitchery.com/articles/format/) says that jpgs are always 24-bit. Is that true?

[greyfeather75]

jpgs are always 24bit

Gifs are 8-bit
jpgs are 24-bit

16-bit was never a widespread image format in and of itself, though it was a common DISPLAY format back in the day - to save display memory - since 16bit displays were acceptible for most purposes

[Meffy]

GIF is 8-bit at most. What you'd get by converting an image to 16 colors then saving as jpg is blurry, artifacted edges and low storage efficiency. The resulting image won't actually contain 16 colors, but also other close relatives. Is it possible for you to show (or PM) a representative image or two?

[Upchurch]

GIF is 8-bit at most. What you'd get by converting an image to 16 colors then saving as jpg is blurry, artifacted edges and low storage efficiency. The resulting image won't actually contain 16 colors, but also other close relatives. Is it possible for you to show (or PM) a representative image or two?
Doesn't matter. The Man was asking for something that doesn't exist. He must be confused with something else.

[kedo1981]

Yea, I don't think JPG does 16 bit either
16 bit would be 1.6 million colors as opposed to 16 million, whats the point
16 bit was more a display setting or maybe some old MAC format

[Meffy]

Oops, I misread 16 bits as 16 colors.

There are two possibilities for "16-bit color." One possibility is 16 bits total, which is pretty much obsolete these days.

The other is 16 bits each for red, blue, and green channels. Unless they're ultra high-res images from a medical scanner or some such, there's little or no point in doing such a conversion. If the additional bits of color info aren't in the original, they won't be in the result either.

So I dunno. I guess get the bossoid to specify exactly what he or she expects to get as the work product.

[edited to correct an error]

[gnome]

Doesn't matter. The Man was asking for something that doesn't exist. He must be confused with something else.

In such a circumstance, would it not work to give The Man what he most likely would need, if he were sane and informed... and merely tell him he has what he asked for? Presumably, he wouldn't know the difference.

[Meffy]

To make a useful suggestion it's probably necessary to know what end use is intended for these graphics. What makes no sense for Web page graphics might be perfectly sane in certain realms. If the company business has to do with scientific or medical imaging, 16 bit per channel graphics would be right at home. Though converting from lower bit depth wouldn't gain anything, it could be Man needs the images in some specialized file format.

All this assumes he didn't just hear somewhere that "16-bit graphics are good" and decide he had to have some of that good stuff. :-} But that kind of stuff only happens in Dilbert, right? ....... right?

[KonTiki]

Actually, 16-bit or even 32-bit per channel High Dynamic Range is becoming quite the thing lately with graphics people. Adobe Photoshop CS supports it. Unfortunately, the GIMP won't support this until they finish GEGL (http://www.gegl.org/), their next-generation graphics library. Don't hold your breath waiting for that to happen.

[Upchurch]

To make a useful suggestion it's probably necessary to know what end use is intended for these graphics. What makes no sense for Web page graphics might be perfectly sane in certain realms. If the company business has to do with scientific or medical imaging, 16 bit per channel graphics would be right at home. Though converting from lower bit depth wouldn't gain anything, it could be Man needs the images in some specialized file format.

All this assumes he didn't just hear somewhere that "16-bit graphics are good" and decide he had to have some of that good stuff. :-} But that kind of stuff only happens in Dilbert, right? ....... right?
Okay, here are the specifics. We've loading these jpgs externally into swfs. Using Flash Player 8 on a regular machine, we have no problems whatsoever. Using Flash Player 7 or on a thin client, we start running into display problems. One jpg won't show while the one next to it might.

If I have the story right, the thin client can usually fix the problem by dropping their display settings to 16-bit color. The Flash Player 7 problem we may have traced back to some faulty headers.

[Meffy]

Ahhh! I begin to see the problem. It's a little like The Man asking for square bolts because round ones won't fit all those square holes. :-} The header problem seems like a strong lead. Good luck to your coworker, however hyphenated.

[edit]
@KonTiki: The graphics library I use has optional (expensive!) 16-bit-per-channel add-ons. I've not needed them yet but given the nature of my work it's good knowing they're there.

[Banbury]

I would also check the capitalization of the filenames of the images. Some programs do consider this when loading files and cannot find images with different capitalizations (eg. JPG instead of jpg). But Windows cleverly hides this from the users unless you activate it in Explorer.