CHDK dng profile generator project

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Offline vit40

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Re: CHDK dng profile generator project
« Reply #30 on: 02 / February / 2011, 04:44:34 »
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aepl,

- first pair of values is for thumbnail image (width 128, height 96) inside DNG. It has 3 colors per pixel (RGB), 8 bits each
- second pair is for raw image from sensor. It has 1 color per pixel (R, G or B), 12 bits each in this case

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Offline vit40

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Re: CHDK dng profile generator project
« Reply #31 on: 02 / February / 2011, 05:15:03 »
quid, here is the profile

http://www.megaupload.com/?d=HCCUJDH2

I used ISO 200 image. Profile made with ISO 400 indeed produces oversaturated shadows, which would boost the color noise. This profile is slightly more saturated than profile for SX200 and there are slight hue differences for some colors, whether that's how this camera renders colors, whether it's slightly different sensor and calibration is different.

For this version, I left color matrix from dng in the profile (like for v1 version for SX200). Using WB as shot would be ok, but WB presets in ACR probably won't work as expected, as temperature and hue calculated by ACR using that matrix are probably both too high. When you make some daylight pictures in fine weather, write what's average color temperature and tint shown in ACR (ACR WB must be set to As shot and camera WB to AWB), and I'll correct color matrix to get it close to daylight preset. You can also make a picture or two with incadescent light and see what is the temperature/tint shown in ACR, so I can also separately adjust color matrix for tungsten illuminant

Vit
« Last Edit: 02 / February / 2011, 08:36:29 by vit40 »

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Offline quid

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  • SX130IS
Re: CHDK dng profile generator project
« Reply #32 on: 03 / February / 2011, 15:44:18 »
Thanks, vit40! Currently I don't have too much time to play with it, but first tests of your profile are very promising :)

Re: CHDK dng profile generator project
« Reply #33 on: 08 / December / 2012, 22:09:58 »
As I mentioned about a month ago, I have plans to generate a new type of DNG profiles for CHDK cameras. This is the idea: put a raw containing a kind of color checker in the camera, use RAW develop function to get jpeg, compare input and output and calculate a profile. Sounds simple, but there are problems - output result is only 8 bit compressed image, so it is not an easy task to get smooth result. Anyway, after long experimenting, I finally have beta version profiles for my A620 and A650, that are producing quite good results. Here is the link

http://www.megaupload.com/?d=6Z3NDQON

Hi vit,

Sorry to revive such an old thread.

Can I copy and try your A620 profile?
The link above is no longer working...

I have the same problem with you to match DNG (generated by CHDK) with JPG.


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Offline vit40

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Re: CHDK dng profile generator project
« Reply #34 on: 17 / December / 2012, 16:44:18 »

Re: CHDK dng profile generator project
« Reply #35 on: 19 / December / 2012, 12:27:31 »
Here it is

http://www.sendspace.com/file/rk0nrm

Thank you Vit!
I'm very excited with this...  :D

One thing I'd like to ask:
by using DCP profile like this, will it "replace" the embedded matrix in the DNG file itself? or it will have a "stacking effect" on the image (so it's like map the image color using the embedded matrix, then map the already mapped color using the DCP profile) ?

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Offline vit40

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Re: CHDK dng profile generator project
« Reply #36 on: 24 / December / 2012, 09:10:23 »
If you select a profile, all information about color rendition are taken from the profile - color matrices and some other metadata from raw file (dng in this case) are ignored

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Offline 1flounder1

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  • Canon SX130 IS
Re: CHDK dng profile generator project
« Reply #37 on: 09 / October / 2016, 05:44:18 »
Hello vit40,

I have recently bought Canon SX130IS too, and that especially for the raw capability. I noticed someone else has done the lens correction profile already which is great, and now I am only stuck with what appears to be slightly washed out colours, especially skin tones, when developing raw. If I understand it correctly, by using your colour correction profile, colours should pretty much match the jpegs. This would be great, however your link is not working anymore (would you be able to upload again?).

First, after reading some articles I thought I would have to buy some calibration chart (like x-rite), but they are quite expensive. Would you think they are superior when colour correcting though?

Many thanks for your great work.

BR,
D

quid, here is the profile

http://www.megaupload.com/?d=HCCUJDH2

I used ISO 200 image. Profile made with ISO 400 indeed produces oversaturated shadows, which would boost the color noise. This profile is slightly more saturated than profile for SX200 and there are slight hue differences for some colors, whether that's how this camera renders colors, whether it's slightly different sensor and calibration is different.

For this version, I left color matrix from dng in the profile (like for v1 version for SX200). Using WB as shot would be ok, but WB presets in ACR probably won't work as expected, as temperature and hue calculated by ACR using that matrix are probably both too high. When you make some daylight pictures in fine weather, write what's average color temperature and tint shown in ACR (ACR WB must be set to As shot and camera WB to AWB), and I'll correct color matrix to get it close to daylight preset. You can also make a picture or two with incadescent light and see what is the temperature/tint shown in ACR, so I can also separately adjust color matrix for tungsten illuminant

Vit


 

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