Hi Nikolaos,
You can use some of the image pre-processing techniques to improve the readability of the image such as:
• Resizing the image
• Converting the image to Gray scale and binarizing the image using appropriate thresholding level
• Noise removal and image sharpening
• Increasing the contrast of the image since low contrast can result in poor OCR
You can also leverage priori knowledge about the text within the image and improve the results by constraining ‘ocr’ to only select the best matches from the character set that you want to match. For example, since you want to read the text ‘200nm’, you can use a character set consisting of digits and the letters ‘n’ and ‘m’ as follows:
>> results = ocr(BW2, 'CharacterSet', '0123456789nm', 'TextLayout','Block');
>> results.Text
ans =
' m39 205 5 1 200nm 1m 0 48mn
3 m6062 1
60 nmn 0019 nn3 3n 0
'
You can then select the required text '200nm' from this result.
For more information about improving the OCR results, you can refer the following link: https://www.mathworks.com/help/vision/examples/recognize-text-using-optical-character-recognition-ocr.html
Hope this helps.
Thanks.
