WBMP WBMP  Mobile phone image handling
Help for
WBMP
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 Disclaimer
 Use
 Problems
 The future
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Designed using
!HTML³
    About this program...
    Purpose: Converting between sprites and mobile phone images
    Author: Richard Goodwin
    Status: Freeware

    This program is © Rich Goodwin 1999; it may be freely distributed if:

    • All files remain intact and unaltered
    • No unreasonable charge is made
    This program uses spr_fsi by David J. Ruck (druck@armclub.org.uk) from his SPRtools collection of bitmap manipulation utilities. Download them from ftp://ftp.armclub.org.uk/pub/pd/druck/
    Version: 1.00 (July 2000)
    Features: Sprite to WBMP conversion; WBMP to Sprite conversion. That's all there is to it folks!
    Web: http://www.goodwin.uk.com/richard/programs/

    Disclaimer

    • If it doesn't work, tough.
    • If it trashes anything, well, that's a good lesson in taking backups.
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    Use

    Drag a WBMP (filetype &f8f; mimetype image/vnd.wap.wbmp) or Acorn Sprite (filetype &ff9) to the iconbar icon and wait for the save box to appear. Save. Repeat until end.

    Example

    WBMP images are a special type of BMP image suitable for mobile phones and other WAP enabled devices; they're only available in black and white with no transparency, palette or any of those niceties, and due to the size of displays on most WAP devices limited in size (128x128 seems a sensible limit to put into the program; the Nokia 7110 for instance only has a display of 96x65).

    To show how similar the BMP and WBMP image format are, here's a little bit of fun...

    1. create an image of about 96x32 in black and white. It has to be a multiple of 32 for this to work.
    2. Flip it top to bottom.
    3. Make this into a BMP (use Creator, Translator, ImageFS etc.)
    4. Load the file into a text editor - one that can do a hex dump such as StrongEd or Zap.
    5. Delete bytes 0 to 61 inclusive.
    6. Add the following four bytes to the start:
      0 0 x y
      (where x is the width of the image and y is the height).
    7. Upload to WML-friendly server, add code to a WML page to display the image, and wayhey, one WBMP.
    Not exactly easy, and restricted to images with sizes that are multiples of 32.

    So, that's where this program comes in. It will convert Sprites to WBMP and WBMP images to black and white hi-res sprites. Note that I haven't limited the Sprites you can drag in to just black and white - I've used the spr_fsi utility to convert Sprites of any colour depth to black and white first. So long as it's nice and small (128x128 pixels max) the program should be able to handle it.

    Obviously it would be better if you used black and white images from the start, as you'd then be able to see what it looks like reduced to that number of colours; it might be that your 24bit image blurs into nothingness in just two colours. Passing your original image though ChangeFSI allows you to not only scale the image down to the correct size but also do things like presharpen the image (so edges show up more clearly), switch off dithering (so you get just plain black and white with no attempt to fake shades of grey, groovy on pictures of faces and other large areas of a similar colour), expand dynamic range (so that a muddy grey picture is made more black and white) and so on.

    Me   Me again
    Big me as a 24bpp JPEG, and little me as a tiny black and white image suitable for WBMP-ising. Although the process did nothing to disguise my ugly mush (although my tongue does look more like a goatee beard in the black and white version), notice how the computer equipment in the background has almost disappeared.

    If you can't be bothered to go through all that then just drop the Sprite on to this program, save the resulting WBMP, and then drop this WBMP back onto the program to save out a Sprite copy as a preview.

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    Problems

    • Help! it won't work on my machine!
      As this is the first release I can't anticipate all problems, but one thing that might cause problems is that the program saves temporary files inside itself. This is because I had a number of problems with users of another of my programs which used the Scrap directory - the proper place for scrap files I guess - because the Scrap directory was full and they hadn't known to clean it out. So, you'll need to copy this program out of it's archive and on to a read/write filesystem; this might cause problems if you're trying to run it over a school network for instance.
    • RAM Transfer doesn't work
      Nope, it doesn't does it? :) Paint is terrible at receiving files anyway (it even barfs at Photodesk, what chance have I got?). Maybe one day.

    The future

    In testing I had Sprites automatically firing up into Paint after they'd been created (from the original WBMP). It might be nice to offer this as an option. I could also trap any double-clicks on WBMP files and automatically force a conversion to Sprite, which coupled with the above option would be pretty neat. It depends if anyone actually uses the program or not!

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    Signing off

    Rich Goodwin
    richard@goodwin.uk.com
    Monday 3rd July 2000

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