PixConverter Unavailable for NET CORE

[Potmos]

The PixConverter and other related seems to not be available when I reference the latest version of the Tesseract package.
Is there any reason for it?

[ArXen42]

I suppose that caused by the fact that System.Drawing is not built into .NET Core standard library, so all the code related to bitmap is surrounded by #if NETFULL ... #endif.

However, System.Drawing is now accessible as a nuget package, so you can probably copy-paste all the neccessary methods and classes from sources into your project. Alternatively, it should probably be possible to add System.Drawing under .NET support here without too much effort and compile fixed version for yourself.

[ArXen42]

Actually, people have already done it.

[chucker]

However, System.Drawing is now accessible as a nuget package

Note that the System.Drawing.Common package is called so because it's not the entire System.Drawing (for instance, ColorConverter is missing), so there may be some limitations.

[ArXen42]

As far as I understand, Bitmap, even if limited, is very useful as common representation of image. I guess most imaging libraries support conversion to/from bitmap.
For instance, one can do all image manipulation with OpenCV, then, at the final stage, convert image to Bitmap and pass it to tesseract.

At least that is probably better than doing conversion by saving image to temporary storage (memory or disk) and then loading it back using another library and much easier than writing complicated conversion code with direct memory access.

[tdhintz]

My experience is that Tesseract is not as effective at recognition on Bitmaps as it is with Leptonica direct load from file. We haven’t attempted to learn why. We just stopped using Bitmap.

[charlesw]

FYI I've split of a new package Tesseract.Drawing, currently in beta, to support using Bitmaps in .net core if they are required. However I would agree with @tdhintz that just using pix should be preferred if possible (not sure why the results would be different though, odd).