I checked the conversion factor between the pixel and the mm, for the two images which I linked in the previous klog. The result looks consistent with past estimations.

Result

I manually fitted the luminous tape on the TCam image using rectangles. (See the attached pdf.) I assumed the tape's width is 1mm. 

• ETMX: the width of the rectangle is 113 pixels. 
  • conversion factor 10/113 = 0.0885 [mm/pixel]
  • the estimated mirror radius is 110/(10/113) = 1243 pixel
• ITMX: the width of the rectangle is 60 pixels. 
  • conversion factor 10/60 = 0.167 [mm/pixel]
  • the estimated mirror radius is 110/(10/60)=660 pixel

Comparison with other estimations

For the ETMX and ITMX, we used the fixed factor in the analysis to extract the mirror center, which is 1246 pixels for ETMX and 630 pixels for ITMX.
The conversion factor, which Dan-san estimated independently, is 0.0885 mm/pixel, and the mirror radius is 1243 pixels. These values of the three results look consistent.
This result is just a quick check. I will fix the values after analyzing other images.