How to find equality of filled rectangles in 2 images

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C#

I am using AForge.Net to develop a OMR system that marks sheets by finding the equality of rectangles filled using a specific colour. using the blobcounter algorithm, it works fine if Microsoft word is used to fill the rectangles in the sheets. the location of objects in both images will be equal but if 2 different human beings (which is the ideal way it should work) fill the rectangles, the location will be slightly different even if it is the same rectangle filled in both sheets, so it will return a non equal value. How do i go about fixing this if possible? the codes looks like this:

// Loop
foreach (Rectangle1 in rects1)
{
foreach (Rectangle2 in rects2)
{
...
// Equality
if (rectangle1 == rectangle2)
{
Console.Writeline("True");