Re: face quantization

[Reiner Steib <reinersteib+gmane@imap.cc>]

On Fri, Oct 28 2005, Didier Verna wrote:

>         I also noticed that given my original jpg faces that are already at a
> size of 48x48, the average quantization I get is 4 to 6 which is quite poor.
> Maybe the size limit of 726 has something to do with it. As it changed in the
> last few months (I cound't find a trace of this in the ChangeLog) ?

It hasn't changed since...

,----[ C-x v g / vc-annotate ]
| revision 6.45
| date: 2003/04/21 11:42:07;  author: kaig;  state: Exp;  lines: +3 -3
| (gnus-face-from-file, gnus-convert-png-to-face):
| Max length of header is 726, not 740.  From Gaute B Strokkenes
| <gs234@cam.ac.uk>.
`----

>         Finally, it might be worth considering that after
> quantization to 4 or 6 colors, 

BTW, would it make sense to decrease by one instead of two at least if
quant becomes small?

--8<---------------cut here---------------start------------->8---
--- gnus-fun.el	14 Oct 2005 18:51:50 +0200	7.10
+++ gnus-fun.el	28 Oct 2005 12:50:42 +0200	
@@ -172,7 +172,7 @@
 			 quant))))
 	(if (> (length attempt) 726)
 	    (progn
-	      (setq quant (- quant 2))
+	      (setq quant (- quant (if (< quant 10) 1 2)))
 	      (gnus-message 9 "Length %d; trying quant %d"
 			    (length attempt) quant))
 	  (setq done t)))
--8<---------------cut here---------------end--------------->8---

> the resulting PNG images are *bigger* than my original JPEG ones.
> So why not using JPG in the headers instead ?

Ask Lars; his specification says PNG.  :-)

Bye, Reiner.
-- 
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