Starting from the upper-left sub window, its image contrast can be adjusted quantitatively as follows. Click the button . A dialog box will appear, in which values of minimum and maximum absolute intensities of the image are displayed. By default these two values are fitted repectively to the minimum (0) and maximum (255) gray levels on the screen. By narrowing the intensity range the image will turn sharper. Oppositely broadening the intensity range will flatten the image contrast. In the present example, when the minimum intensity is set (in the left data box) to -8 instead of -16.9 and the maximum intensity is set (in the right data box) to 40 instead of 59.7, the image contrast will be changed to that in the lower right window. Actually the result does not appear in a new sub-window but just replace the image in the original sub-window. If you wish to keep the result, You would save it manually before attempting to close the window.
The following is an example, though nothing crystallographic, demonstrating the ability of contrast adjustment provided by VEC.
Step 1:
Starting from
the original image on top-left, click the button
. Put '220' in the left data box of the dialog box and click 'OK'. The
result will be that on top right.
Step 2:
Starting from
the image on top-right, click the button
. Put '20' in the right data box of the dialog box and click 'OK'. The
result will be that on top-left.