Red points in DNG photo - page 2 - RAW Shooting and Processing - CHDK Forum
supplierdeeply

Red points in DNG photo

  • 19 Replies
  • 6057 Views
Re: Red points in DNG photo
« Reply #10 on: 20 / October / 2012, 07:37:10 »
Advertisements
DNG 1.2 : I am not a technician to understand the dedicated wiki page about it,
so if one can answer me in simply way :
- how are the improvements respect 1.1 version ?
- why not implemeted in CHDK and "jumped" directly to 1.3 ?
Thanks in advance.

Re: Red points in DNG photo
« Reply #11 on: 20 / October / 2012, 08:22:18 »
DNG 1.2 : I am not a technician to understand the dedicated wiki page about it,
so if one can answer me in simply way :
- how are the improvements respect 1.1 version ?
- why not implemeted in CHDK and "jumped" directly to 1.3 ?
Thanks in advance.
The only change implemented in CHDK DNG between 1.1 and 1.3 was that 1.3 no longer applies bad pixel correction in the camera.  This means it does not need a badpixel.bin file.

This change was made because many people were having trouble creating badpixel.bin files using CHDK on their cameras.  The reason for that is unknown but it might be due to small sensor reading variations from picture to picture that the code to create a bad pixel file did not like. 

Using 1.3 should also be slightly faster as the camera no longer needs to process the badpixel.bin file for every shot.

DNG 1.2 was not implemented because nobody volunteered to do it.   Probably because there was not a good reason to do it.   As mentioned above,  DNG 1.3 was only implemented to solve a CHDK problem on some camera, not for an photographic reason.

Ported :   A1200    SD940   G10    Powershot N    G16

*

Offline reyalp

  • ******
  • 13439
Re: Red points in DNG photo
« Reply #12 on: 20 / October / 2012, 15:37:06 »
Another reason to use 1.3 is that the badpixel.bin can take a substantial amount of memory. On some cameras, this is enough to cause problems.

It's also worth pointing that except for the handling of bad pixels, all RAW / DNG produced by CHDK have exactly the same image data.
Don't forget what the H stands for.

*

Offline ramja

  • *
  • 10
Re: Red points in DNG photo
« Reply #13 on: 20 / October / 2012, 19:26:54 »
The only change implemented in CHDK DNG between 1.1 and 1.3 was that 1.3 no longer applies bad pixel correction in the camera.  This means it does not need a badpixel.bin file.

This change was made because many people were having trouble creating badpixel.bin files using CHDK on their cameras.  The reason for that is unknown but it might be due to small sensor reading variations from picture to picture that the code to create a bad pixel file did not like. 

Does this mean that it would not be too hard to put the code back into CHDK to apply badpixel.bin to 1.3 DNGs?

Using 1.3 should also be slightly faster as the camera no longer needs to process the badpixel.bin file for every shot.

Yes, but quite tolerable - with "show raw processing time" on 1.1 showed 28xx, 26xx and 13xx; 1.3 showed 13xx, 16xx, 16xx

DNG 1.2 was not implemented because nobody volunteered to do it.   Probably because there was not a good reason to do it.   As mentioned above,  DNG 1.3 was only implemented to solve a CHDK problem on some camera, not for an photographic reason.
Another reason to use 1.3 is that the badpixel.bin can take a substantial amount of memory. On some cameras, this is enough to cause problems.

It's also worth pointing that except for the handling of bad pixels, all RAW / DNG produced by CHDK have exactly the same image data.

So... from the above 2 quotes does that mean that there is no difference between CHDK created 1.1. and 1.3 DNGs? More specifically: Is CHDK adding opcodes and parameters to the 1.3 DNGs?

Here's my basic issue - I have always used CHDK for bracketing and DNGs. Picasa, IrfanView, and Photomatix would seamlessly handle the 1.1 DNGs. If CHDK-created 1.3 DNGs include opcodes and parameters that I may want to take advantage of at some point in the future I will have to make a big adjustment in my PP workflow. I will have to run the 1.3 DNGs through an Adobe product first to take care of badpixels, then into Photomatix for HDRs.

Do CHDK-created 1.3 DNGs have the additional opcodes, functions and parameters that could prove valuable now or in the future? Or is the difference between the 1.1 and 1.3 DNGs just in minor header and data structure changes (and thus no reason to add extra steps and storage to PP)?


Re: Red points in DNG photo
« Reply #14 on: 20 / October / 2012, 19:33:02 »
Does this mean that it would not be too hard to put the code back into CHDK to apply badpixel.bin to 1.3 DNGs?
That would defeat the only reason it was done.

Quote
So... from the above 2 quotes does that mean that there is no difference between CHDK created 1.1. and 1.3 DNGs?
Yes (except for the bad pixel corrections done in 1.1)

Quote
More specifically: Is CHDK adding opcodes and parameters to the 1.3 DNGs?
No.
Ported :   A1200    SD940   G10    Powershot N    G16

*

Offline reyalp

  • ******
  • 13439
Re: Red points in DNG photo
« Reply #15 on: 20 / October / 2012, 20:12:01 »
Does this mean that it would not be too hard to put the code back into CHDK to apply badpixel.bin to 1.3 DNGs?
Currently, the *only* difference between CHDK DNG 1.1 and DNG 1.3 is the use of opcodes for the badpixels. If you want to use badpixel.bin, then use DNG 1.1.
Quote
Is CHDK adding opcodes and parameters to the 1.3 DNGs?
The only opcode used is the badpixel opcode. In the future, it's possible we might support more. Lens correction would certainly be nice.
Quote
Here's my basic issue - I have always used CHDK for bracketing and DNGs. Picasa, IrfanView, and Photomatix would seamlessly handle the 1.1 DNGs. If CHDK-created 1.3 DNGs include opcodes and parameters that I may want to take advantage of at some point in the future I will have to make a big adjustment in my PP workflow.
I expect that programs which do not support badpixel opcodes (which are quite simple to implement) won't support the other more complicated ones.
Don't forget what the H stands for.

*

Offline ramja

  • *
  • 10
Re: Red points in DNG photo
« Reply #16 on: 20 / October / 2012, 22:48:14 »
waterwingz:

Thanks for the clarification. :D

nafraf finished up the 1.00a port for my Elph310 just a couple of days before I spent a week in Yosemite and Bishop, CA. Shot a lot of 1.3 DNGs that I'll have to run through PS, but at least it is a one-time effort.

Re: Red points in DNG photo
« Reply #17 on: 20 / October / 2012, 23:06:46 »
Shot a lot of 1.3 DNGs that I'll have to run through PS, but at least it is a one-time effort.
There are a lot worse stories of people shooing important things with CHDK without really testing anything first and getting a nasty surprise.   Sounds like you should be okay and at worst,  you still have the jpegs.
Ported :   A1200    SD940   G10    Powershot N    G16


*

Offline philmoz

  • *****
  • 3332
    • Photos
Re: Red points in DNG photo
« Reply #18 on: 20 / October / 2012, 23:24:01 »
waterwingz:

Thanks for the clarification. :D

nafraf finished up the 1.00a port for my Elph310 just a couple of days before I spent a week in Yosemite and Bishop, CA. Shot a lot of 1.3 DNGs that I'll have to run through PS, but at least it is a one-time effort.

The 'dng_validate' program in the Adobe DNG SDK can convert a DNG to a TIF file and it will apply the bad pixel removal opcodes during conversion. Be sure to use the '-16' parameter if you want 16 bits output per RGB channel.

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)
  g5x (1.00c, 1.01a, 1.01b)
  g7x2 (1.01a, 1.01b, 1.10b)

*

Offline I2k4

  • *
  • 28
Re: Red points in DNG photo
« Reply #19 on: 26 / December / 2012, 13:44:43 »
Very odd - I've been unaware of the DNG 1.3 in newer CHDK or any incompatible models.  On my SX10 I simply produced badpixel.bin as usual and have no problem with the output. 

However I found this thread researching a problem with colored flecks in the DNGs from my new Ixus 300/SD4000, which is still in "beta" - changing to 1.1 and redoing badpixel.bin has normalized RAW/DNG output on that camera - I'd never have guessed.  Thanks for the cure.
Appreciative end-user for several years:  S5is, SX10is, and SD4000is.

 

Related Topics