Manipulating Raw Picture Data

[viktoras didziulis]

just played around a little with this handler on 600x500 image (MS 
Windows XP, RR 2.9, Intel Celeron 1500 MHz):

on  repColor
local myData
local myTimer
local myColor1
local myColor2

put binaryEncode("C3",myRed,myGreen,myBlue) into myColor1  
put binaryEncode("C3",myRed2,myGreen2,myBlue2) into myColor2
 
  put the milliseconds into myTimer
  put the imageData of img "im1" into myData 
  replace myColor1 with myColor2 in myData
  set the imageData of img "im1" to myData
  put (the milliseconds) - myTimer & return after fld "fTimer"
end repColor

in development environment with paintcompression set to default ("PNG") 
it takes around 635 milliseconds.
If before loading your image you do this: set the paintcompression to 
"RLE" (which is the default in standalones)
the same color replacement handler takes just 77 milliseconds, which is 
~ 9 times faster!

Now if only we'd know what exactly rle format is used by RR, then we 
should be able to do:
put the text of img "im1" into myData 
replace myColor1 with myColor2 in myData
set the text of img "im1" to myData

unfortunately now this damages the image but otherwise it would take 
only ~25 milliseconds.

All the best!
Viktoras


Mark Greenberg wrote:
> I have an image where different regions consist of known colors. I 
> would like to fill a region with color at runtime as a sort of 
> highlight. The situation does not lend itself to using separate 
> transparent png images. I have been using the floodfill bucket tool to 
> achieve this, but it is slow and doesn't work right when I compile to 
> standalone.
>
> I've read various threads on manipulating the raw picture data and 
> seen a couple of stacks like that. It seems a bit beyond my skills as 
> a casual programmer, but I may need to give it a try. Two questions: 
> would sampling every pixel in a 600x400 image and possibly changing 
> the pixel's color be fast enough to seem like a highlight to the user? 
> and how would I go about doing that?
>
> Thanks in Advance,
>
>     Mark Greenberg
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