Size-optimized badpixel format

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Offline srsa_4c

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Re: Size-optimized badpixel format
« Reply #10 on: 26 / November / 2013, 11:39:31 »
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I have created a new "badpixel.bin" with half the size of the previous version.
This utility is more like a research tool or a possible implementation of the above (poorly) described compression methods. In its current form it can compress uncompressed badpixel files into the v6 and v7 format and vice versa. If you fed in-camera badpixel.bin into it as source, it decoded the file incorrectly. You can make uncompressed badpixel file by decompressing an in-camera badpixel.bin with the v1 method.
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But what do i have to do now to use the new v7 badpixel.bin (With the new "badpixel.bin" the camera {SX230HS 1.00c CHDK trunk3230} crash) ?
These compression methods can not be implemented for "badpixel.bin" files, because those files don't have any file header. Since CHDK expects its own data format, it doesn't check whether the data it reads is valid, thus it will crash if you provide a badpixel.bin with unexpected data. In changeset 3228, philmoz has implemented an improved variant of his RLE compression, which is now default in CHDK. Try re-creating badpixel.bin with a current CHDK version (don't forget to update _dng.flt), it will now be much smaller on CMOS cameras like yours.

My methods don't offer enough size improvement over the newer RLE compression to justify further work.

 

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