Sharp and OCR

[kayz1]

I have a few questions about image preprocessing for OCR. I would like to know to what extend I can use Sharp in following tasks:

• image DPI - is there a Sharp method for increasing image DPI?
• Illumination - what Sharp methods can I use to fix lightning and increase contrast?
• Binarize - what Sharp method can I use to convert image to black and white (not grayscale)?
• Denoise - what Sharp method can I use to remove noise from image?

[lovell]

Hello, DPI doesn't really mean anything when using bitmap images on screen as it's a print concept.

Please see median for a de-noise operation, threshold for a "binarize" operation and #609 for brightness and contrast.

[lovell]

@kayz1 Hope this answered your question, please re-open with more details if further help is required.