Trouble recognizing digits in Tesseract - android

Question

I was hoping someone could tell me why it is my Tesseract has trouble recognizing some images with digits, and if there is something i can do about it. Everything is working acc

Answer 1

Tesseract doesn't do segmentation for you. Tesseract will do a thresholding of the image prior to the actual tesseract algo. After thresholding, there may be some edges, artefacts that remain in the image.

Try to manually modify your images to black and white colors and see what tesseract returns as output.

Try to threshold (automatically) your images and see what tesseract returns as output. The output of thresholding may be too bad causing tesseract to give bad output.

Your 4th image will probably fail due to thresholding (you have 3 colors: black background, greyish background and white letters) and the threshold may be between (black background, greyish background).

Generally Tesseract wants nice black and white images. Preprocessing of your images may be needed for better results.

For your first image (with the result "04"), try to see the box result (char + coordinates of box that contains the recognized char). The "0" may be a small artefact - like a 4 by 4 blob of pixels.