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CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit

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Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #40 on: 17 / January / 2009, 10:54:23 »
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Awesome! Keep up the rocking work man!

Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #41 on: 17 / January / 2009, 18:05:32 »
Can anyone give me instructions on how to get it to work?  I've followed all the instructions I've found on the CHDK Wiki, but nothing works. 
I have a 4GB SDHC Card (Sandisk Extreme III) and I have formatted that as FAT16 as it apparently needs to be.

Some instructions say it just needs to be formatted to FAT16, others say it needs to be 'made bootable'.  Which is correct?
Any pointers?

Thanks for the good work (can't wait to test it when I can make it work) :)

EDIT: Just worked out what I was doing wrong - I do need to make the card bootable, so I used Card Tricks.  Now it's working fine - just gotta learn what it all does now, and hope for the final release with everything in soon, thank you so much :D
« Last Edit: 17 / January / 2009, 18:45:43 by ROGUE »

Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #42 on: 18 / January / 2009, 13:09:16 »
Mhh, which brings us to the question if a simple diff from the IXUS 85 applied to the FW of IXUS 90 would work... (maybe with a few hunks). As far as I know the two cameras ar identical except the display size (resolution of the screen ist identical thougt on the IXUS 90 it is 3" screen) and the controllwheel.

Sadly I am not a coder (except bash and python and that  knowledge is way not enought to do some debugging on the cam) I would try to boot the the IXUS 90 mod which was patched against the modded IXUS 85 dump. So sharky, if you coud patch the IXUS 90 dump and post the DISKBOOT.BIN... I would giv it a shot...

Great WORK!!!

Kind regards
blubbi

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Offline reyalp

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Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #43 on: 18 / January / 2009, 16:12:06 »
Mhh, which brings us to the question if a simple diff from the IXUS 85 applied to the FW of IXUS 90 would work... (maybe with a few hunks). As far as I know the two cameras ar identical except the display size (resolution of the screen ist identical thougt on the IXUS 90 it is 3" screen) and the controllwheel.
No, it almost certain the memory addresses are different. They are usually different between different canon firmware versions of the same camera, never mind different models.
Don't forget what the H stands for.


Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #44 on: 18 / January / 2009, 18:00:16 »
Awesome work! Bought a IXUS 85IS pre-christmas just because I wanted to try CHDK and hopefully learn to have fun with RAW photo. And finally "I'm up and running"!

(Well, bought the cam because my Ixus 500 were just about to die, and i wanted a possible chdk-compatible camera, so the 85IS were the cheapest and most avaliable at the moment)

Keep up the great work, fellas!

Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #45 on: 19 / January / 2009, 01:37:40 »
My Cam has crashed a few times now when making RAW pics.

please report if you have this problem too.

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Offline igvk

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Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #46 on: 19 / January / 2009, 02:19:55 »
Sharky,

Thanks for the great work!

So, how did you modify badpixel.lua to support 12-bit RAW?

And, do you have a patch for dng4ps2 or you convert CRW with your own program?
I looked at reader.c in one of your messages. Why do you reduce the resolution to half of the original?

Sorry, I'm new to CHDK, so maybe it is well-known knowledge.




Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #47 on: 19 / January / 2009, 05:26:19 »
badpixel.lua is still the same; the bad-pixel detection itself it inside core/raw.c which I have updated for 12-bit pixels

I used that reader.c but it is old now, I have attached a new one which also works in win32 .. Easiest is to use DNG support inside your camera now.

The reason it outputs half the resolution is simple: your CCD has resolution 3720x2772. BUT this does NOT mean it has 3720x2772 RGB pixels; each of the 3720x2772 is EITHER Red, OR Green OR Blue in a grid. The two first lines of pixels are

RGRGRGRGRGRGRG
GBGBGBGBGBGBGB

So you see that the easiest way to make an RGBRGBRGBRGB image (as normal), just to take each block of

RG
GB

As one pixel. The reader just discards the second G, and writes one RGB per 2x2 block of RGGB pixels. If you were to do it properly, you'd interpolate between all the values, giving you a 3720x2772 RGB image (this is what your cam does when generating JPGs). So in some sense of the word, this camera really is not 10MP, but just 2.5 MP. This goes for just about any digital camera though :) On the other hand, if you photograph something black-and-white, each pixel counts and you get a 'true' 10MP image (with R=G=B).


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Offline igvk

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Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #48 on: 19 / January / 2009, 05:52:06 »
I see now.
So, if you wish to keep as much luminance information as possible, it's better to still use the whole resolution and interpolate color (hue) values. Am I right?
(And - there is no way for the moment to use dng4ps2, it's better to use dng output in CHDK)

Actually, my question on badpixel.lua came from the fact that I get about 10000 bad pixels using the script as it is. :(
I think that's because there is lots of noise in extra bits of pixels in this camera.
I don't think that I have that many bad pixels..
And without the badpixels.dat I am unable to use DNG save format.

P.S. You are doing much appreciated work, sharky!  :)

Re: CHDK for PowerShot SD770 IS/DIGITAL IXUS 85 IS: Update: Pg2 RAW in 12bit
« Reply #49 on: 19 / January / 2009, 06:34:54 »
10000 is about right (that's still only 1 in 1000 pixels)

I have 11991 dead pixels.

I heard from others that this is a fairly medium amount of dead pixels. The dead pixel detection is quite easy since dead pixels give a value of exactly ZERO, there is no threshold or anything. (black pixels are at around 0x80 or so in 12 bit resolution)

about interpolation: I'm no color theory expert, but the problem in taking luminance directly and interpolating chrominance (hue) is that hue changes in adjacent pixels will show as luminance changes, probably giving you strangely glowing edges and stuff. The 'normal' way would be to go over each pixel, take one component color (R, G or B) that you know (directly from the RGGB data) and interpolate the other two. I think this kind of algorithms have been well-researched and are well-understood, so it's probably a better idea to use an existing program which does interpolation like dcraw.

That said, I'm working on my own HDR (commandline) rendering engine just for the hell of it ;)

 

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