Reading A is a small reconstruction of one part of OCR: visual comparison and classification.
The prototype begins with a single reference image, an Arial “A.” Every test image is converted into black and white, cropped, scaled to the same size, and compared with this reference. The system calculates how much the two shapes overlap and produces a similarity score. Based on a decision boundary that I set, the result is labeled A, A?, or UNKNOWN.
I tested the system with different typefaces, handwritten and photographed letters, rotated forms, similar characters, geometric shapes, and different color conditions. Through these tests, I found that the system does not have a general concept of what the letter A is. It only knows the specific A that I selected as its reference.
The experiment also showed how much information disappears when an image is simplified for machine comparison. Colors, materials, and other visual qualities can be lost during binarization before the comparison even begins.
Most importantly, I found that the final answer depends not only on the input or the similarity score, but also on the threshold I choose. Changing the threshold can change the output without changing the image or the measurement.