Grain counting tutorial

• First convert the image to grayscale using Color..Color->Grayscale.
• In Grain counting, leave the defaults unchanged and click on "Count grains". The size distribution graph should be displayed.
• Some images may have a very large number of grains with a size of "1". This can cause the size distribution graph to appear blank. If this happens, increase the Minimum Size, and click on "Restore original", and click on "Count grains" again. It is not necessary to close the graph window; the program will re-use the same graph window. The buttons on the left can be used to re-scale the graph if necessary.
• To save the data in a file, click on "Save to file" on the graph or "Save results" on the Grain Counting Dialog box.
• To get rid of the graph, click on "Dismiss".
• If the program is drawing big boxes around large sections of the image, it means there is too much signal in the image. Change the threshold and repeat.
• If the program is finding areas that are too big (for example, by drawing a large box around the entire image), change the Maximum size.
• If the image has an uneven background, it may be necessary to enhance the spots or flatten the background (or both). To enhance the spots, click "Enhance spots". This will apply a specially-designed edge-filter to the image that makes the outlines of the spots darker.
• To flatten the background, select "Force background to fixed value" in the filter menu. A larger filter kernel produces a smaller background flattening effect.
• If there are stray marks on the image, such as lines around the edge of the image.the image may need to be cropped or edited to remove them.