How to interpolate or remove black pixels in DNG files

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Offline philmoz

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Re: How to interpolate or remove black pixels in DNG files
« Reply #10 on: 27 / March / 2012, 03:53:40 »
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That's annoying, sorry about that.

http://www.box.com/s/678e641c1c95f9320064
http://www.box.com/s/c8d16625ea4d9bbe3f82
http://www.box.com/s/a943d9b255ffafc5a31c

It could be the same problem that was found on the ixus220.

Try the attached version and see if it makes any difference.

Phil.
CHDK ports:
  sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
  g12 (1.00c, 1.00e, 1.00f & 1.00g)
  sx130is (1.01d & 1.01f)
  ixus310hs (1.00a & 1.01a)
  sx40hs (1.00d, 1.00g & 1.00i)
  g1x (1.00e, 1.00f & 1.00g)

Re: How to interpolate or remove black pixels in DNG files
« Reply #11 on: 28 / March / 2012, 15:01:13 »
Excellent! I'll try it tonight. If you have a moment (you seem pretty busy with helping other members), I'd love a brief explanation of what is actually going on for my own edification. Seems like a mismatch between what is mapped as a bad pixel and what is actually removed from the DNG...

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Offline philmoz

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Re: How to interpolate or remove black pixels in DNG files
« Reply #12 on: 28 / March / 2012, 15:10:22 »
Excellent! I'll try it tonight. If you have a moment (you seem pretty busy with helping other members), I'd love a brief explanation of what is actually going on for my own edification. Seems like a mismatch between what is mapped as a bad pixel and what is actually removed from the DNG...

It depends if this version works or not.

CHDK considers any pixel on the sensor as bad if the value is 0.
For the IXUS220 it was found that values up to 16 were occurring as bad pixels.
Your images look very much like those I checked from the IXUS220 so I've enabled the same fix to test this theory.

Phil.
CHDK ports:
  sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
  g12 (1.00c, 1.00e, 1.00f & 1.00g)
  sx130is (1.01d & 1.01f)
  ixus310hs (1.00a & 1.01a)
  sx40hs (1.00d, 1.00g & 1.00i)
  g1x (1.00e, 1.00f & 1.00g)

Re: How to interpolate or remove black pixels in DNG files
« Reply #13 on: 29 / March / 2012, 17:46:43 »
Wow! Looks like this fixed it! I'll continue to shoot tonight and make sure but based on my preliminary trials with slow shutter speed and small aperture, I'm not seeing any hot or black pixels. Thanks!!

On another note, is there any way to have the camera boot straight into shooting mode with the lens extended? It always goes into playback mode on start and I have to half-depress the shutter to get the lens to extend. I haven't been able to find an option to change this. Thanks again, Phil.


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Offline philmoz

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Re: How to interpolate or remove black pixels in DNG files
« Reply #14 on: 29 / March / 2012, 18:12:42 »
Wow! Looks like this fixed it! I'll continue to shoot tonight and make sure but based on my preliminary trials with slow shutter speed and small aperture, I'm not seeing any hot or black pixels. Thanks!!

Excellent, I'll add the fix to SVN.
Did your bad pixel count go up by much?

Quote
On another note, is there any way to have the camera boot straight into shooting mode with the lens extended? It always goes into playback mode on start and I have to half-depress the shutter to get the lens to extend. I haven't been able to find an option to change this. Thanks again, Phil.

That's by design in CHDK.
By the time CHDK gets to the code that determines which button was used to start the camera (on/off or playback/review) the information is lost (unless you hold the button down).
To avoid problems for users who might start the camera with the playback button, not expecting the lens to extend, CHDK defaults to playback mode.

If you hold down the on/off button for a bit longer CHDK will see this and start up in record mode.

Phil.
CHDK ports:
  sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
  g12 (1.00c, 1.00e, 1.00f & 1.00g)
  sx130is (1.01d & 1.01f)
  ixus310hs (1.00a & 1.01a)
  sx40hs (1.00d, 1.00g & 1.00i)
  g1x (1.00e, 1.00f & 1.00g)

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Offline hwntw

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Re: How to interpolate or remove black pixels in DNG files
« Reply #15 on: 30 / March / 2012, 05:02:48 »
Hello, I tried Philmoz build for my Ixus300 HS and I experimented with creating badpixel.bin. I could not make it work at any ISO greater than 400 (ditto with my own compiled build). The process kicked off but ended with *could not create badpixel.bin* at these settings. I usually shoot at 200 ISO so that is what I used to create the file successfully. I doubt that my eyes will allow me to see any bad pixels, anyway.

Colin
PS Very willing to help with improving CHDK on this brilliant camera, will test if asked
Ixus 300HS S100


Windows 10

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Offline philmoz

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Re: How to interpolate or remove black pixels in DNG files
« Reply #16 on: 30 / March / 2012, 05:13:57 »
Hello, I tried Philmoz build for my Ixus300 HS and I experimented with creating badpixel.bin. I could not make it work at any ISO greater than 400 (ditto with my own compiled build). The process kicked off but ended with *could not create badpixel.bin* at these settings.

Did you try at telephoto zoom - at the wide end of the zoom it can have trouble in the corners due to the lens distortion.

Phil.
CHDK ports:
  sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
  g12 (1.00c, 1.00e, 1.00f & 1.00g)
  sx130is (1.01d & 1.01f)
  ixus310hs (1.00a & 1.01a)
  sx40hs (1.00d, 1.00g & 1.00i)
  g1x (1.00e, 1.00f & 1.00g)

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Offline hwntw

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  • 158
Re: How to interpolate or remove black pixels in DNG files
« Reply #17 on: 30 / March / 2012, 09:11:09 »
Hello, I tried zooming and I created BPB at 800 ISO. Failed at 1600 and 3200.

Colin
Ixus 300HS S100


Windows 10


Re: How to interpolate or remove black pixels in DNG files
« Reply #18 on: 30 / March / 2012, 12:27:08 »
I had luck with creating at ISO 800 in relative good daylight and f5.6 or f.80 at wide angle

Re: How to interpolate or remove black pixels in DNG files
« Reply #19 on: 02 / July / 2012, 02:00:39 »
I have the exact same problem with the exact same camera and tried to install the attached files, but somehow they are not recognized. When I go to the menu to select 'Firmware update', I don't see the entry in the menu anymore. When I go back to the old version, I do see it again and can execute the update again.

Any ideas?
 

That's annoying, sorry about that.

http://www.box.com/s/678e641c1c95f9320064
http://www.box.com/s/c8d16625ea4d9bbe3f82
http://www.box.com/s/a943d9b255ffafc5a31c

It could be the same problem that was found on the ixus220.

Try the attached version and see if it makes any difference.

Phil.

 

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