implement PrepareDistortedPix as part of DegradeImage

[Shreeshrii]

Fixes #1052

[amitdo]

Shree, I don't think mixing the distort & degrade methods is right.

Basically, the distort method should be directly called from text2image.cpp.

[amitdo]

Why -0.9?

I think it should be kept as 0 (50% percents of images inverted).

[amitdo]

Also,

• Todo -> TODO (like in other places in the codebase).
• Why are you keeping the commented code in DegradeImage()?

[Shreeshrii]

0 (50% percents of images inverted).

Is that a realistic expectation of the types of images which will be OCRed?

[Shreeshrii]

• Todo -> TODO (like in other places in the codebase).

OK.

• Why are you keeping the commented code in DegradeImage()?

I meant to delete it after the changes to text2image worked fine. I will fix that.

[amitdo]

0 (50% percents of images inverted).

Is that a realistic expectation of the types of images which will be OCRed?

Generally no, but...
If you want good accuracy for inverted images, you should train with enough samples.

[Shreeshrii]

If you want good accuracy for inverted images, you should train with enough samples.

OK, that makes sense. I will change it to 0.

Thanks!

[amitdo]

Thanks!

Thank you too :-)