Re: [avr-chat] Storing B&W bitmap images into Flash : file format suggestion ?

[Jim Brain]

On 1/9/2010 9:11 PM, Vincent Trouilliez wrote:
> Hi list,
>
> - What's the usual/easiest file format that people use, to store 1-bit
> (black and white) bitmap images/pictures ?
>    
That may be the question you've asked, but I'm not sure it's the right 
one to ask.  You want to store the binary data in FLASH in the smallest 
format possible that does not require lots of computation to decode.

For the pic, I think you should store the data as RLE data in FLASH.  
Then, write some little C app on Windows or Linux that takes BMP or GIF 
or whatever and converts it.  A quick app can easily take a BMP and 
output a C source file that defines a PROGMEM array of bytes.  Add the 
utility step to Makefile, include the resulting C file in your 
compilation, and you're done with storage.  RLE decoders are trivial to 
write, and you've got a space optimized graphic in FLASH that can be 
easily displayed.

For the bitmap, I'd do something similar.  Write a small C app that takes:

Chars.txt:

 ***
*   *
*****
*   *
*   *

...

Or whatever, and converts it into a 2-D array in C source code.  include 
it as you compile, and you're done.

From a font perspective, the above has been done before.  Just pull 
some usable source from someone, as there are lots of C source charsets 
out there.

Jim