Calculate an Image Sensor Resolution Spacing (Pixel Size)
Enter the height and width of the image sensor
Search Digital Photography Review for the camera manufacturer and model, select the specifications page and note the sensor size (0.1 - 1000.0 mm).
If the sensor size is specified as 1/x.x", get the sensor height and width from the table in the Image Sensor Format article in Wikipedia.
Enter the numbers of columns and rows
Enter the maximum resolution (100-100,000) in columns and rows (also available from Digital Photography Review).
Enter the actual resolution (100-100,000) of the images in columns and rows if a lower sensor resolution is being used. In Windows, right click on the image file, select Properties and then Details.
If the maximum and actual values are the same, leave the actual values as zero.