[Canon already has it] Hot Pixel Mapping.

Started by feureau, February 12, 2013, 06:54:30 PM

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feureau

Dead/hot pixel: pixel stuck in a certain condition that it would leave a spot in your JPEG/video. To clear this out, one must put on the body cap to the body, turn on manual sensor cleaning, wait for 30 seconds, and hope it triggers the hot pixel mapping function. The way canon hides the hot pixel mapping function this way is beyond me, but if there's a way for ML to trigger this function, that would be awesomely useful.

Hot pixel mapping tutorial: http://www.youtube.com/watch?feature=player_embedded&v=WJBuGhMnvFo

So this has been requested, but there's no response from anyone. I hope a dev could chime in on what ML can do regarding this topic.

feureau


a1ex

Since Canon already does it, what's the point?

1%

Never had a camera broken like this so didn't even know it existed except for factory functions.

SpcCb

Quote from: a1ex on March 04, 2013, 03:08:27 PM
Since Canon already does it, what's the point?
I'm agree with feureau; Canon Frw do that _in theory_ but it's not really working fine.
You can test it by recording an 1fps/1s exp. video @2500ISO with ML (extreme config, for enlighting). Don't wast your time to run sensor cleaning, even for 1hr or ten times, hot pixels will be not filed.

Note, I'm using custom hot pixel map on CHDK and it's very nice. Good bye hot pixels, even in 1024s exposure on a small SX200.

ariznaf

Canon already has it by firmware, but resulting correction is written in the file as metadata.
Thus, only the Canon DPP software uses that data to eliminate hot or dead pixels (or even dust).

Many of us use Adobe ACR or other software to develop, and thus this function is useless and cannot automatically correct dead pixels.

It would be great if ML could use the dead pixel information and write the RAW file with the dead pixels corrected, interpolated from their neighbour pixels.

hjulenissen

Quote from: ariznaf on March 25, 2013, 01:29:32 PM
It would be great if ML could use the dead pixel information and write the RAW file with the dead pixels corrected, interpolated from their neighbour pixels.
Seems to make more sense that Adobe enables the meta-data interpretation in ACR?

-h

ariznaf

Of course that would be the optimal solution, but I don't expect them to do it. May be it is not even possible for them it the metadata is encrypted in the raw (I don't know it it is).

May be it is easier if you have access to Canon's internals in the firmware, but I don't know if it is easy or even possible.

But it would be of great help to make Canon's functions of dust removal and dead/hot pixels elimination usefull to people who don't use Canon DPP.

1%

Heh, I found a red pixel in 6D that comes up at high ISO... but only in video. Sensor cleaning does nothing. Maybe should look into this.

Betelgeuza

Quote from: ariznaf on March 25, 2013, 01:55:49 PM
Of course that would be the optimal solution, but I don't expect them to do it. May be it is not even possible for them it the metadata is encrypted in the raw (I don't know it it is).

May be it is easier if you have access to Canon's internals in the firmware, but I don't know if it is easy or even possible.

But it would be of great help to make Canon's functions of dust removal and dead/hot pixels elimination usefull to people who don't use Canon DPP.

i use DPP and i must say i used  stamp tool there ( its same stuf u used ? ) and when new window  coming up its eazy to remove hot pixels with this but  changes never saved on  main photo :DD . changes are visible only in Stamp edit  window but when i done with dis  red mad pixels are in same place what before.. with PS removiing  [ pixels  is  muche more eazy .. alsow  auto sensor cleaning in  my T3i i fell like is more for show not for do job..

ariznaf

I don't use dpp,  just tried it a few times.
Yes,  it is supposed that there is a hot pixel removal automatically using the stamp feature., based in the info from raw meta data. No
I haven't used it,  just for trial.
But it is not used in other soft like acr  or dark table.

1%

Or video :)

[DDD] is dust delete data... found references to ypack.raw and dustmap.raw

[Defc] Is defect correction for YUV/VIDEO... that is the one to look into for hot pixel mapping.

Sapporo

Is it confirmed that the manual sensor cleaning thing is the real way of remapping the sensor? What I know, Canon denays it. I have tried my self and it worked, but I want to know why it worked.