Q score Problem

[BD LEE]

Hello,  My name is Lee. 

I am inquiring about some problems while using your program. 

I would like to compare the HDR image I created with the Ground Truth HDR images with HDR-VDP2.2.2.
So I organized the following code and tried to simulate it.

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T_HDR = double(hdrread('17_0_generated_hdr_drago.hdr'));

R_HDR = double(hdrread('17_0_gt_hdr_drago.hdr'));

ppd = hdrvdp_pix_per_deg( 21, [size(T_HDR,2) size(T_HDR,1)], 1 );

res = hdrvdp( T_HDR, R_HDR, 'rgb-bt.709',ppd)

imshow (hdrvdp_visualize (res.P_map, T_HDR))

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And we printed the results, and the C_max value was 2018.6 and the Q Score was 81.7973.

When I saw your explanation, the value of C_max should be 1, which I think is clearly wrong.

Could you tell me what part of me was wrong?


Thank you so much. It is also an honor to use your simulation. 

 

 

[Rafal]

The code looks OK. But make sure that both images are scaled in absolute units, as explained at:  http://hdrvdp.sourceforge.net/wiki/index.php/Frequently_Asked_Questions; the diffuse white should have a value of around (200,200,200).

C_max is 1 if the most visible difference is just noticeable. The most visible difference is clearly visible in case of your images. 

Q is not scaled in absolute units (it does not go to 100), but value around 80 suggests the quality is rather high. 

You can try HDR-VDP-3, which should be better calibrated for the task of comparing two images side-by-side. 

Rafal

[LEE, BD]

Thanks for your Kindness! 

2020년 11월 5일 (목) 오후 5:16, Rafal <man...@gmail.com>님이 작성:

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