The value of the FRC map is all NaN

[yrl1120]

When I use eSRRF->Parameters sweep-->Calculate FRC, the value of the FRC map is all NaN, I am confused about why this is happening, and is there any way to avoid or solve it, I would appreciate it if you could answer me.

[HannahSHeil]

Hi, could you try again with a different crop of the image? This sometimes happens if the FRC estimation is not able to optimize. If it only happens for single parameter pairs in the sweep those will be disregarded, but if it happens for the whole sweep, either your parameter range is very off or your image area does not fit well.

[yrl1120]

Thank you very much for your reply. Now I have some confusion about calculating FRC and error maps, if we have 1k frames raw image sequence, and we split raw data into odd/even frames and reconstruct it (500 frames), is the corresponding raw sequence also reconstruct with 500 frames? Compare error maps with this result(500 frames)? It means that 1000 frames are divided into odd (500)/even (500) frames to calculate the resolution value, should we also choose frame number 500 for raw image sequence reconstruction? I would appreciate it if you could help me.

[HannahSHeil]

Hi,
you always need the double amount of frames for the parameter sweep and it will for example only create a reconstruction out of 500 of the 1000 frames. In the final reconstruction you can use the information of all 1000 fr, this could give slightly better results. Maybe there is no detectable difference, just try it.

[yrl1120]

Thanks for the reply, I'll try it. So this means that the input of 1000 frames is actually calculated at the FRC resolution of 500 frames reconstruction?