Reducing colors to 4096 before saving?

Hi. I want to reduce the colors in a picture to 4096 before I export/save it as jpeg. (I think that's 12bit color if I did the math correctly.) I am saving this on my cell phone and since the phone itself only supports 4096 colors, I am confident the PShop will do a better job downsizing it than my cell phone.

Cann you point me in the correct direction to do this?

Thanks!

Joshua,

Any particular reason why you would want to use a cell phone and its relatively miserable 12-bit color capabilities to archive pictures?

Neil

LOL. Did I say anything about Archiving? While an interesting response to my question, I was hoping for something a little more helping then questions my motives or my cell phones miserable capabilities.

Joshua,

I'm equally perplexed by your question. While I wouldn't question anyone's motives, a little further elaboration might be conducive to someone being able to reply to your inquiry, perhaps by offering an alternative solution.

Two points:

1. I have a plugin which does this. The non-dithering version can be downloaded here <http://www.telegraphics.com.au/sw/#12bits> (it's called "12bits"). For the dithering version, please contact me by e-mail.

2. It's pointless saving as JPEG after doing this reduction. In short, JPEG's encoding cannot preserve any particular RGB subset of colours (you can prove this to yourself by re-opening the JPEG; I also offer above a plugin that counts actual distinct RGB colours used in an image).

If the phone software can render a JPEG image directly, then don't bother with any colour reduction. If it can't render a JPEG directly, then what format does it actually use? (TIFF?) That's the format you need to target.

Ahh. Well I'll try to explain a bit more...

I am working on an application to send graphics to cell phones... aka, when your wife calls you, her picture shows up, etc.

One of the phones in particular can't display more than 4096 colors and when we send it a full jpeg, it seems to reduce it to a 4096 pic in a less than flattering way. So I figured that pshop would do a better job.

That make more sense?

Thanks.

-- Joshua

Hmm...maybe you could profile the phone's screen and Image>Mode>Convert to Profile?

With a profile you could SoftProof: PS> View> ProofSetUp> Custom> Phone

You probably need to use PNG:
<http://www.cellmedia.com/detailedarticle.shtml?aid=3>

Joshua,

Thanks for a little more explanation. As far as my reference to "archiving" images to your cell phone, you did say "I am saving this on my cell phone." I just took it from there.

But some day, we'll be able to save high-res images to our cellphones, much as we can to better digital cameras. <vbg>

Neil

If the phone uses a palette with 4096 entries, you'd have to write custom quantization software (an export plugin could do it).

If the phone is 4096 colors continuous (4 bits/16 values each of R, G, B) -- you can achieve that with the posterize command.

What is the RG smilie face?

Another reason to get rid of these stupid emoticons.

Apparently Upper Case B followed by close parentheses... Glasses and smile. I agree, the smilies are obnoxious.

You can turn Emoticons on and off in your forum preferences.

That applies to Emoticons inserted by others too. Uncheck the Show Emoticons box in Miscellaneous Settings and you won't see any Emoticons at all.

If the phone is 4096 colors continuous (4 bits/16 values each of R, G,
B) -- you can achieve that with the posterize command.

Great idea, I didn't think of that. But you can't get error diffusion that way. OTOH, you can add about 16 units of uniform white noise before posterising to get a random dither.

Thanks for the emoticon tip, Ramón, I've never changed a preference so quick.

Note: Smiley in post 9 is deleted.

Emoticons!

Neil

That applies to Emoticons inserted by others too. Uncheck the Show Emoticons box in Miscellaneous Settings and you won't see any Emoticons at all.

I'm aware of this, but just because I can't see it or turn it off doesn't mean the rest of the world who has not turned it off will not see the stupid Emoticon. I think its a problem that we can't type a sentence with out the damn forum software deciding what it is we are saying or not saying.

The Emoticons are a bad idea and its time to get rid of them. or at least not have then translated into our text automatically.

%D :) %( :D >:( :X

The problem is Fraudian: the fault lies in the nose!

To kill emoticons, just make sure that you don't use a hyphen for the nose -- tildes are a good replacement.

:~)

Fraudian?

Maybe it's Digimarc's CDS searching for fraud.

Or maybe Freudian?
Noses searching for Fraud.

Actually emoticons are probably all the fault of Digimarc.

Or maybe Freudian?

Noses searching for Fraud.

Freud'sche Fehlleistung? Maybe a Freudian slip by a feminist Frau.

Everything is Digimarc's fault.