SK-AM62A-LP: LSC Tuning output

Hi Atharva,

Atharva Shende said:

so after adding this spec_file we are not getting proper tunning graph

Yes, that plot shows that tuning is not done properly.

Did you follow the plugin guide to input all the required information correctly?

Atharva Shende said:

2. For IMX219 we have this spec_file

This is good for lens spec.

Did you follow the plugin guide and convert it to the proper format?

What is the proper format of that spec file

Hi Atharva,

Please take a look at the LSC plugin guide under the help menu of tuning tool.
The input LUT for tuning tool has the 1st column in the unit of pixels.

Hello Gang Hua,

Just tell me if I want to remove Greenish at center through LSC then what shape graph should i get so that i can work accordingly.

Or if you have any reference graph for same then it will be helpful.

This is my current Graph:




This is the LUT file which we are currently using in which left column is number of pixels and second column is relative Illumination:

0   1
49   0.9998
103   0.9991
152   0.998
205   0.9965
254   0.9874
308   0.9838
357   0.9694
411   0.939
460   0.9209
513   0.8983
563   0.8669
616   0.8452
665   0.8187
718   0.7831
768   0.7515
821   0.7052
871   0.6671
924   0.6096
973   0.5619
1027   0.4733

Thanks

Atharva Shende said:

This is the LUT file which we are currently using in which left column is number of pixels and second column is relative Illumination:

Simple LSC LUT like this is for making the image corner as bright as image center (i.e., undo lens shading).
That won't change any color.

Atharva Shende said:

Just tell me if I want to remove Greenish at center through LSC then what shape graph should i get so that i can work accordingly.

Color shading may be handled by applying different LSC gains on the R/G/B channels.
As the shape of these R/G/B LUTs are different, it can change the color of things.
You will have to calibrate your lens and find out different LUTs for R/G/B pixels.

Tuning tool does not support this directly if I remember correctly.
You may have to use the tuning tool to generate xml files from R/G/B input LUTs and manually interleave the gains for the final xml file.

Gang Hua said:

Simple LSC LUT like this is for making the image corner as bright as image center (i.e., undo lens shading).
That won't change any color.

Then which LUT will remove the greenish colour at the center

Atharva Shende said:

Then which LUT will remove the greenish colour at the center

It is the combination of all R/G/B LUTs.

For example, around the image center, we would expect to have R and B gains higher than G gains in your case.

That shall change the greenish tone around image center.
However, as the amount of color shading may change according to the type of lighting you have, you may have to adapt LSC tuning to lighting conditions.
If you don't have much experience or the necessary H/W equipment for ISP tuning, it is much easier to use a better camera-lens module.

Gang Hua said:

You will have to calibrate your lens and find out different LUTs for R/G/B pixels.

Can you tell me how I can take different raw images with R/G/B 

Atharva Shende said:

Can you tell me how I can take different raw images with R/G/B 

I am not sure if I understand you correctly.

Raw image is the same, but LSC LUTs are different.
The raw sensor image is in Bayer RGGB pattern.