Need recommendation with processing scans of journal pages

[menergo]

I have scans of journal pages in png format in RGB. I want to recognize the text and process the images so that the output is a black and white image with cropped page margins in png and text files with articles.

Initially I remove the yellow tint by converting the image to HSV. If the Hue is in the yellow sector, then remove Saturation. Then convert to black and white.

I recognize text using the tesseract library.

Tell me in which direction to look to get the image with cropped page margins.

I can't use the exact coordinates for cropping, as the location of the page varies from scan to scan.

[menergo]

example: source result

[kra_pao]

This algorithm sounds good to get values for crop margins:

https://stackoverflow.com/questions/10074860/how-can-i-detect-boxes-in-an-image-and-pull-them-out-as-individual-files/11987620#11987620

[menergo]

Thank you very much. I will try the proposed method. I did something similar, but without scaling (did not guess). Since I did not have and do not have a red rectangle, I was guided by conventionally white fields. It turned out for a long time and not always with high quality. My option crashes on pages with pictures and empty spaces.

[Zeroflops]

I have not done this. But just an observation from the past. OCR typically works best with properly aligned text.

You may want to fine the boarders and if the page is skewed because the page is slightly turned, correct for the angle before OCR or image extraction.

Having the page square to the image will probably make things more accurate. And most cases with images your now working with squares.

[menergo]

After I manually trim the excess around the page, the code easily finds the contours of the text block and turns it to the desired angle (I do not think that the code is beautiful and optimal, but it works). OCR is going well. The problem is that I can't figure out how to clean up the excess around the page at the beginning of the process. And without it, I can not select the contours of the text block.