I have a lot of marked boxes that are not correctly identified as marked.

Can you click on Zooms in the Data capture tab after having selected a page where a lot of boxes are badly detected, and post the window with the zooms?

Thanks for your quick response. I have attached an example of what you ask for.

As you can see, some boxes have scores 0.38, 0.47 and (a dark) 0.87, but other boxes have scores of 0.009. I put the B/W threshold at 0.6 and the darkness threshold at 0.01 (as I cannot make it any smaller).

Mateo.

1. first a grayscale to B/W conversion takes place (using the B/W threshold to separate white from black)
2. then AMC counts the number of black pixels over the total number of pixels in each box. If this ratio is over the darkness threshold, then the box is declared to be ticked.

On the zooms window, the number written along with the boxes is the darkness ratio computed at step 2. Looking at your zooms, we can see that the darkness ratio is very low even if the box is fully darkened. So the problem comes from the first step: grayscale to B/W conversion. So you have to play with the B/W threshold value first, so that the ratios in the zooms window represents accurately the proportion of the box that is darkened. Please try a higher value for B/W threshold.

Best approach: Scan right away in b/w, not in greyscale.