NAME

       myrescue-bitmap2ppm - Visualisation of the block bitmap for myrescue

SYNOPSIS

       myrescue-bitmap2ppm bitmap-file width [ rows width ] ...

DESCRIPTION

       myrescue-stat  reads a block bitmap from myrescue(1) and generates a visualisation of each
       blocks condition.

       The image is written to stdout in PPM(5) format. You can pipe the output into one  of  the
       netpbm converters or into ImageMagick(1) to convert it to a more common format like PNG.

       Successfully  copied  blocks  are  shown as green pixels. Yellow-green-ish pixels indicate
       blocks that could be copied, but it took unusually long, indicating that this  area  might
       be  near-failing.  Yellow  blocks  have been tried once, but could not be read, red blocks
       could not be read on multiple attempts.  Black pixels indicate blocks that  have  not  yet
       been handled.

       The  pixels  are arranged left-to right, with the first block in the upper left pixel. The
       width of the image must be specified on the command line - just  pick any value.

       In case of partially defective discs you might start by having myrescue do a random  jump-
       around  scan  (option  -J)  and  continually check the visualized block bitmap. If you are
       lucky, you might begin to see some structure in the image. If these structures somehow run
       diagonally,  you  can  adjust the width until you get vertical stripes of defective areas.
       What this means depends on the internal layout of the disc,  but  it  could  be  defective
       heads, platters, sectors, cracks, a factory workers hair, ...

       Usually  internally  discs  have different zones, so after a few (hundred?) rows you might
       see the vertical structures bend off. To adjust the image, you can tell the tool to switch
       to  a different width after a certain number of rows. Repeat this until you identified all
       zones. The last width will be used up to the end of the bitmap.

       The resulting image will have the maximum width necessary to accommodate all zones.  Zones
       with shorter widths will be padded on the right with blue pixels.

       You  can  now use this information to manually fine-tune the myrescue calls to concentrate
       on areas with higher probability of rescue.

AUTHORS

       Kristof Koehler <kristofk@users.sourceforge.net>

SEE ALSO

       myrescue(1), ppm(5), ImageMagick(1)

       http://myrescue.sourceforge.net/