Test stack "speed of imagedata processing and paintcompression"

Richard Gaskin ambassador at fourthworld.com
Mon Jun 4 08:07:05 CDT 2007


I had thought that you'd earlier discovered the difference between MC 
and Rev to be simply that Rev's boot script changes the default 
compression.  This would imply that anyone who uses MC or any other 
collection of stacks as their IDE could bring the same performance in 
any other IDE by simply changing the paintCompression back to the 
engine's default.

What am I missing?

-- 
  Richard Gaskin
  Fourth World Media Corporation
  ___________________________________________________________
  Ambassador at FourthWorld.com       http://www.FourthWorld.com


Wilhelm Sanke wrote:
> I have submitted a bug report to the "Revolution Quality Control Center" 
> (what a modern neoliberal term) to which number 5113 was assigned.
> 
> I post the report to this list, too, because those Metacard users that 
> intend to make a transition to the Revolution IDE may run into 
> unexpected difficulties when they deal with imagedata processing in 
> their stacks.
> 
> The default setting for the paintcompression in all engines is RLE. The 
> Revolution IDE changes that setting to PNG, which is then transferred 
> even  into Rev standalones via an encorporated script.
> Rev users would be well advised to set the paintcompression to RLE (or 
> at least to JPEG, which is only slightly slower) in their openstack 
> handlers.
> 
> Here is the text of my report:
> 
> "There is a test stack with test and result pages that demonstrate the 
> reported effects (you need of course to launch the stack with the 
> different engines).
> 
> <http://www.sanke.org/Software/TestStackPaintcompression.zip>
> 
> Because of the included test images and a possible "full-screen" view 
> the stack has a zipped size of 14 MB. I stripped my emerging Photo Tool 
> down to four filters and three images, the first with 5 different sizes, 
> the other two with a size of 2048x1536.
> Derek Bump's "convolve.dll" is included.
> 
> Apart from the individual structure of the respective script, the speed 
> of imagedata processing depends on two additional factors:
> - to some extent on the engine version (and IDE),
> - as a more important factor on the paintcompression.
> 
> The fastest engine is version 2.6.1 (Metacard 2.6.6). The speed 
> difference to engine version 2.8.1 - while using the same 
> paintcompression - can reach 33% (compare the results for the 
> "scripted-matrix-version filter").
> 
> Concerning the factor paintcompression, the most extreme results of the 
> tests demonstrate that using PNG paintcompression can be up to *twelve 
> times* slower than wih RLE.
> The speed difference extends to 400% when looking at the results for 
> applying the DLL, PNG paintcompression is here four times slower than 
> RLE, JPEG is somewhat slower than RLE.
> One test concerned the retrieval of image contents - size 2046x1536 - 
> from imagedata and compressed imagedata stored in custom properties. 
> With the paintcompression set to PNG, image retrieval is up to twelve 
> times slower than with RLE. In this case, there seem to be only minor 
> engine influences. "
> 
> An addendum I sent today to the improve list:
> 
> "Contrary to the fact that PNG paintcompression may slow down the speed 
> of imagedata processing considerably, "text-of-image" data are 
> apparently not affected, as you can see when you use button "sample 
> image - five sizes" of the test stack, which stores the image contents 
> as text-of -image data."
> 
> 
> --Wilhelm Sanke
> <http://www.sanke.org/MetaMedia>
> 
> 
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