Anyone using CHDK for RAW files?

I just recently installed CHDK on a Canon Powershot 780 12 Megapixel Camera.

I’m looking for samples from anyone who is using CHDK or some other process to retrieve RAW files from these compact cameras.

I’m very impressed with CHDK, and with these new compact cameras, being able to produce a RAW files is at once exciting, but also points out some of the inherent problems with these small compact cameras in the 10+ MP range.

On the Powershot 780, for example, once downloading a DNG file through CHDK, it’s clear that color noise is rampant with this camera and that the pre-processing in the camera, among other things, actually blurs the colors in the image to reduce the noise (legal disclaimer: this is just my opinion from looking at the data).

There’s also a large amount of other CCD noise.

I’m looking for anyone who can send me RAW .DNG samples (and the camera-written JPEG) from similar compact cameras through CHDK (or another methods to extract RAW data).

Based on my results so far, I’ve been able to do some pre-processing that the camera can’t do for lack of time. From what I’ve seen across the web (which is a small set), I can see these problems inherent in the RAW-based originals.

With the limited file set I have taken myself, I’ve been able to get results from the RAW files that have been a marked improvement over the JPEG, by using different noise-removal methods. I’ve also been able to use highlight reduction methods to increase the dynamic range, as well.

I’d like to do more testing and create a development path to working with these RAW files and enhancing (greatly) the pictures possible from these compact cameras.

If you’re interested in contributing samples, please e-mail me at rob@sagelighteditor. I’m looking for ones I can use in RAW (.DNG) vs. JPEG fashion, and am looking for aesthetic shots, like landscapes, flowers, people, etc. I’d want files I can feel free to use without restriction (I mean, to showcase as before/after examples).



17 thoughts on “Anyone using CHDK for RAW files?

    • Yes. It’s the exact type of camera I’d like to see RAW images from. Are these from CHDK (or something like that), or does it write RAW files on its own? If you could send me on directly, that would be great. I can see if I can load it or if I need some program. I have Adobe’s RAW-to-DNG program, but it doesn’t work on the CRW files I have from the 780. Interestingly, Adobe Photshop CS2 doesn’t open the .DNG files written out through CHDK, either.

      If you could ftp a representative sample to (user name: anonymous, password: password), that would be great!

      • Hi, David.

        Thanks for the samples. Sorry for the delay in my reply. I had that data corruption issue that not just set me back, but disoriented me a little, too. I’ve been spending time making sure everything is backed up as completely as possible.

        I like the pictures, especially the one with the women and the ballons. Do you have the original RAW files, by any chance?


      • Hi Rob,

        Sorry about that. I used Picasa to “export” from my RAW folder and it looks like it converts to JPEG rather can copying. I’ll resend.


      • I guess that makes sense. When you save what original started as RAW files in Sagelight, it defaults to jpeg, too. I’ll look forward to seeing the RAW vs. jpegs…

      • Hi Rob,

        I’ve uploaded some CRW files now. I couldn’t remember which iones I sent, so if you want the CRW or JPEG version of a file that you already have, send me the file names and I will upload.


      • Thanks for sending the RAW files. Where did you take all of those? Very nice. I used one of them in the blog. I’m slowly seeing how to get some better quality out of these smaller CCDs…

        I’ve definitely seen that the 12mp powershot I have just doesn’t seem to have any greater quality than an 8mp the same size. I’m hoping to leverage the higher resolution against all of the noise that gets created with it.

      • Hi Rob,

        Most of the shots were in Vietnam (the one you used and the “colourful” ones).

        I deliberately sent one with LOTS of noise for you to play with (that one is Hong Kong harbour).

        Yes, I was very impressed with the output from the Canon IS720. Outstanding quality for the price.


        david J

      • They’re very nice. I am not sure if I am impressed with the 12MP 780 Powershot yet, but I’m probably trying to get more out of it than it is meant to deliver for its class. I’m thinking that these tiny 12mp cameras don’t make much sense at the 12mp level. It almost seems like there is more quality to be gained by using less megapixels.

        I thought the one I used of yours was very colorful, as well. Which one was the noisy one you referred to?

      • Hi Rob. Thanks for the comments. The night scene of Hong Kong harbour (CRW_1611.CRW) is pretty noisy. I gues with the 780, they’re getting to the limit of pixel density for sensors of that size. I also have a range of Olympus RAW file (.ORF) if you want to explore them. I upgraded to a DSLR finally.

  1. Hi Rob,

    I have a “Canon Powershot S3 IS” running CHDK and it saves in .CRW format as well. Is this something you would be interesed in?

    .DNG is Apple MAC format isn’t it?

    I have set the CHDK to save .DNG files but it doesn’t seem to work and saves to CRW instead. How did you set it up?

    • Yes, that would be great! Thanks.

      DNG is the Digital NeGative format from Photoshop.

      To get CHDK to write DNG files, I had to first get a “badpixel.bin” file. This was done by letting it write a .CRW file, and then running a file called “show_bad_b.exe” on it. It produces a set of bad pixels from the CRW files and writes badpixel.bin. Then, I put badpixel.bin in the CHDK directory on the flash card. After that, CHDK would let me select .DNG format, and it’s been writing to .DNG files ever since.

      Which is nice, because I haven’t been able to find any way to open the .CRW format written by my Powershot 780. And, the recommended manner is to download a file that I can only find on Russian Sites that Mcafee tells me not to trust. On a recommendation, I downloaded “bad_pixel_b.exe” from a russian site, and it worked. I put it at It runs under CMD in Windows — and I absolutely cannot take any responsibility for it, so use it at your own risk! It did work for me, though.

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