thanks, not sure what kind of help i would ask for at this point. i noticed
that your flattened histogram even with a slightly improved fitting
procedure that i just tested (will push later, doesn't really help all that
much so far) has a 2x noise std deviation for dark regions. some other
cameras have way worse behaviour than that for brightnesses < 0.2, but
maybe this is enough to confuse the algorithm. i fitted a gaussian to that
error and instructed the wavelet denoiser accordingly, but so far results
aren't a lot better than what we had before.

i could get way better results using the equalizer and manually pulling up
the threshold for the chroma channels (start from `chroma denoise' preset
and push it to the extreme basically).

i hope to do some more tests on that tomorrow.
j.



On Tue, May 28, 2013 at 6:21 AM, Baptiste Pierrat <
[email protected]> wrote:

> I´m willing to help if you want more samples or else (I´m not a good coder
> but I have some basic knowledge).
>
>
> On Mon, May 27, 2013 at 2:50 PM, johannes hanika <[email protected]>wrote:
>
>> hm. if anything your sensor is cooler now and has less constant noise
>> added on top. the data in your image matches your previous measurements
>> very closely. i'll have to do some more digging.
>>
>> j.
>>
>>
>> On Mon, May 27, 2013 at 1:46 PM, Baptiste Pierrat <
>> [email protected]> wrote:
>>
>>> Well I did the profiling for my camera and it's currently this one that
>>> is used in the code (git master). I took great care in doing this
>>> correctly, I did 4 profiles and averaged the results.
>>>
>>> Here is the raw file from the previous example if you want to test:
>>> https://www.dropbox.com/s/iqb04gly913vmfx/20130429_0041.ARW
>>>
>>> The problem for me is not only the green pixels but also the bigger
>>> cross-shaped blue and red dots. Isn't that somehow related to the
>>> demosaicing process?
>>>
>>> Thank you for helping with that.
>>>
>>>
>>>
>>>
>>> On Mon, May 27, 2013 at 1:27 PM, johannes hanika <[email protected]>wrote:
>>>
>>>> hm. that looks reasonable. very surprising that those green pixels
>>>> still stay in the color buffer. maybe the profiling doesn't match your
>>>> particular camera model? maybe the profile was a little off for that
>>>> particular iso value, or maybe there is some variance between individual
>>>> sensors for sony cams?
>>>>
>>>> i can try and re-profile that particular raw and see if there are any
>>>> differences to the data we have if you want.
>>>>
>>>> j.
>>>>
>>>>
>>>> On Mon, May 27, 2013 at 12:14 PM, Baptiste Pierrat <
>>>> [email protected]> wrote:
>>>>
>>>>> [image: Inline image 1]
>>>>>
>>>>>
>>>>> On Mon, May 27, 2013 at 12:12 PM, johannes hanika 
>>>>> <[email protected]>wrote:
>>>>>
>>>>>> what are the white balance coefficients for that image?
>>>>>>
>>>>>>
>>>>>> On Mon, May 27, 2013 at 11:57 AM, Baptiste Pierrat <
>>>>>> [email protected]> wrote:
>>>>>>
>>>>>>> Hello,
>>>>>>>
>>>>>>> I want to second this problem.
>>>>>>>
>>>>>>> I have a Sony Alpha 57 and have a lot of trouble with remaining
>>>>>>> bright color dots after denoising. My usual denoising tools for iso>800 
>>>>>>> are
>>>>>>> :
>>>>>>> 1. Chroma denoise: profiled denoising with wavelets, blend with
>>>>>>> color, then
>>>>>>> 2. Luma denoise: profiled denoising with non-local means, blend with
>>>>>>> lightness
>>>>>>>
>>>>>>> Here is an example with an iso 3200 sample:
>>>>>>> original: http://minus.com/lU783RXDLcLH7
>>>>>>>  chroma denoised: http://minus.com/lBe1kgj6o5aoP
>>>>>>> chroma and luma denoised: http://minus.com/lbqRsDO5q4E617
>>>>>>> detail after export: http://minus.com/lCLmKR1s2vh5a
>>>>>>>
>>>>>>> Green, red and blue larger dots remain. Also notice as chroma
>>>>>>> denoising does not work well for green color. As suni, this problem is
>>>>>>> partially solved by using the color smoothing option in demosaic but the
>>>>>>> image is slightly blurred.
>>>>>>>
>>>>>>> Thanks!
>>>>>>>
>>>>>>>
>>>>>>> On Mon, May 27, 2013 at 11:25 AM, johannes hanika <[email protected]
>>>>>>> > wrote:
>>>>>>>
>>>>>>>> you left in all the luma noise in your lightroom comparison image.
>>>>>>>> to do that in darktable, use `color' blend mode in the profiled 
>>>>>>>> denoising
>>>>>>>> module. you may want to use the wavelet method, it is usually a little 
>>>>>>>> more
>>>>>>>> effective against color noise.
>>>>>>>>
>>>>>>>> j.
>>>>>>>>
>>>>>>>>
>>>>>>>> On Mon, May 27, 2013 at 11:21 AM, suni <[email protected]> wrote:
>>>>>>>>
>>>>>>>>> Hi all,
>>>>>>>>>
>>>>>>>>> I'm fighting the high ISO noise of my A550 camera, but I still
>>>>>>>>> cannot achieve the reasonable output. Even the new profiled denoise 
>>>>>>>>> filter
>>>>>>>>> doesn't help much.
>>>>>>>>>
>>>>>>>>> Below is the example of the ISO12800 image. I do not take images
>>>>>>>>> on such high ISO but it makes this problem more visible for this 
>>>>>>>>> purpose.
>>>>>>>>> This behaviour may be observed even at ISO1600 and higher. The RAW 
>>>>>>>>> image
>>>>>>>>> below is totally unaltered RAW for comparison opened side by side in 
>>>>>>>>> dt and
>>>>>>>>> in Lt. Only the base curve is applied at dt side because otherwise the
>>>>>>>>> image looks very ugly and not comparable to the Lt from the visual 
>>>>>>>>> point of
>>>>>>>>> view.
>>>>>>>>>
>>>>>>>>> Link to unaltered RAW image:
>>>>>>>>> https://dl.dropboxusercontent.com/u/9454436/sony_noise/raw_not_altered.jpg
>>>>>>>>>
>>>>>>>>> As you can see the image looks almost the same in both tools. Just
>>>>>>>>> note the bright red dots. The Lt shows less of them especially on the 
>>>>>>>>> right
>>>>>>>>> side of the paper Christmas tree. These red dots cannot be removed by 
>>>>>>>>> any
>>>>>>>>> of the dt denoising filters unless the image becomes almost blurred.
>>>>>>>>>
>>>>>>>>> Now see the next image below. This shows what can be achieved in
>>>>>>>>> dt and in Lt. While only activating the luma and chroma denoise 
>>>>>>>>> sliders in
>>>>>>>>> Lt produces the acceptable and (to me) pretty usable output where 
>>>>>>>>> only some
>>>>>>>>> luma noise remains, with dt I cannot achieve similar output by no 
>>>>>>>>> means.
>>>>>>>>> The most strange finding is that no one from all the denoising filters
>>>>>>>>> available in dt can remove these bright red dots unless it is pushed 
>>>>>>>>> to not
>>>>>>>>> acceptable high strength producing the blurred image. The only 
>>>>>>>>> strategy I
>>>>>>>>> found to be somehow working here is as follows:
>>>>>>>>> 1) turn off the sharpen filter
>>>>>>>>> 2) apply the hot pixel filter at its maximum strength
>>>>>>>>> 3) set the color smoothing of the demosaic filter to maximum
>>>>>>>>>
>>>>>>>>> These three steps do remove the bright red dots. But the image
>>>>>>>>> still suffers of the high chroma noise. The only possible way to get 
>>>>>>>>> rid of
>>>>>>>>> it while maintaining the image sharpness at the level comparable to 
>>>>>>>>> the Lt
>>>>>>>>> I found is the profiled denoise set to less than default strength. 
>>>>>>>>> But as
>>>>>>>>> you can see there still remain far more chroma noise than in the Lt 
>>>>>>>>> case.
>>>>>>>>>
>>>>>>>>> Link to altered RAW image:
>>>>>>>>> https://dl.dropboxusercontent.com/u/9454436/sony_noise/raw_altered.jpg
>>>>>>>>>
>>>>>>>>> Because I've got to that point I didn't know what to do more,
>>>>>>>>> I profiled my camera. But even though my profile seems to me to be a 
>>>>>>>>> bit
>>>>>>>>> better than the one packed with dt, it produces no visible difference 
>>>>>>>>> here.
>>>>>>>>>
>>>>>>>>> I would like to ask all of you experienced in fighting the high
>>>>>>>>> ISO noise for your experiences and recommendations. It would be great 
>>>>>>>>> to
>>>>>>>>> get to know that the problem is in between the chair and the 
>>>>>>>>> keyboard, not
>>>>>>>>> in the excellent dt tool!:-)
>>>>>>>>>
>>>>>>>>> If someone is interested, the original RAW image can be found
>>>>>>>>> here:
>>>>>>>>> https://dl.dropboxusercontent.com/u/9454436/sony_noise/DSC09533.ARW
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Thank you in advance for any reply!
>>>>>>>>>
>>>>>>>>> Suni
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> ------------------------------------------------------------------------------
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>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
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>>>>>>>> Try New Relic Now & We'll Send You this Cool Shirt
>>>>>>>> New Relic is the only SaaS-based application performance monitoring
>>>>>>>> service
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>>>>>>>> browser, app, & servers with just a few lines of code. Try New Relic
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>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>

<<image.jpeg>>

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