Linear to Log scale

[camillamello]

I need to calibrate a picture graphic using Log Scale, but I am having troubles to do it. To  accomplish this calibration I have one 512px x 512px picture; then I may click the pixel I want to be the 10 on my log scale. After that my software shall calculate the sacale for me. My problem is: the picture is divided in 512 linaer lines. How can I solve this problem?

Thanks

[altenbach]

What is the representation of each pixel. Is this greyscale.

What do you mean by 512lines? 1D arrays? Typically you can just apply the scaling to the entire array.

Could you attach a simple version of your program so we have a better idea of the problem?

[camillamello]

This  program illustrates my problem, thanks for your attention.