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RLE encoded images - Realtime display? — Parallax Forums

RLE encoded images - Realtime display?

Ken once wanted to show PowerPoint slides using a Propeller:
http://forums.parallax.com/discussion/140056/running-a-presentation-from-a-propeller-putting-a-bmp-in-vga/p1

Phil came up with some kind of real time compressed image decode to do something interesting.

Was just thinking about this in terms of P2 and 1080p display.
Seems there's this ancient image format called PCX that implements some kind of RLE encoding.

See the attached example. Irfanview can show it. It's a fairly complex, 256 color, 1080p image that comes in at 215 kB.
Forum software won't let me attach a .pcx image, so I zipped.

If it could be decoded faster than the frame rate, might be in business...
There's room for two of this size image in HUB RAM...

I found some c++ code here that looks like it can decode pcx:
https://github.com/mackron/dr_libs/blob/master/old/dr_pcx.h

Comments

  • kwinnkwinn Posts: 8,697
    Run Length Encoding would be a relatively simple to implement and effective method of encoding some images, particularly those for HMI's. For an HVAC system the compression ratios were between 40 to 1 and 90 to 1 depending on which area of the system was being displayed.
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