RAW data format - RAW Shooting and Processing - CHDK Forum

RAW data format

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RAW data format
« on: 27 / July / 2008, 05:21:15 »

I am trying to view the RAW raw data in the CRW using python and when i read the lines, it outputs a sequence of characters like this:


what does this mean?

My guess: if crw is supposed to be 10-bit depth, and if i convert the \xc1 to hex, it would mean that its only 8-bit long? Am i wrong?

Re: RAW data format
« Reply #1 on: 28 / July / 2008, 22:31:32 »
If you are writing some code please check the source code of raw_merge.c.
If you are just trying to display the picture dcraw.c is a good starting point.

General idea: Let's say that you have 8 values of 10bits. Put them end to end in a 80 bit stream. Slice the 80 bit stream into 10 bytes. Swap the bytes around (depending on the endianess of the CPU). You will then get the mix here.

Have fun...


Offline LjL

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Re: RAW data format
« Reply #2 on: 29 / July / 2008, 08:11:22 »
\xc1 is already a hexadecimal value. It's "C1" preceeded by a standard escape sequence.

And yes, any two-digits hexadecimal number fits in one byte. Look at this snipped of raw_merge.c, specifically, for the details on reading Canon raw.


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