I am really struggling to understand what I'm doing wrong, appreciate any assistance you can give.
I have one layer that is a vertical strip with graduations and numbers 0-43000
its dimensions are 88x22858 pixels
I have another layer that is a rolling type odometer.
I created a null layer which the vertical strip layer is moved vertically, ie in they Y axis.
the number of the y position is then multiplied by a factor to cause the odometer to roll and match the vertical scale.
unfortunately when I get to the the oppotite end of the scale it is a little out.. if I calibrate it at the centre, then its out a little at each end. any ideas ? thanks..
Hard to tell since we can only guess how much pixels in Y occupy those numbers, how offset those are, so measure yourself what is the actual distance between e.g. baseline of number 0 and number 43000. Then, have you taken in account that you have to take in account also the first/last number of scale? Assuming that it is really 22858.0px, then if Y-min is 0, then Y-max should be = (22858.0 - 22858.0/43001)