Add viewport for PB743K3

[SilverGreen93]

The bezel covers a couple of pixels of the screen, so adjust not to show content under the bezel.

This fixes #11301

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This change is 

[NiLuJe]

I wouldn't mind someone with the same device double-checking that this isn't just shoddy build quality on your particular device ;).

That's not to discount the fact that some OEMs do like to put bits of screens behind bezels, but it's usually in a slightly less wonky fashion (i.e., one side only, usually top or bottom).

[diegopau]

@NiLuJe @SilverGreen93 I just tested this in my PocketBook InkPad Color 3.

I used the nightly build koreader-pocketbook-v2023.10-82-g5d2a44106_2023-12-29 from https://build.koreader.rocks/download/nightly/v2023.10-82-g5d2a44106_2023-12-29/

I used the PDF sample that I attach here so you can compare with the same reference.

I set KoReader to "auto" page crop and 0.00 margin.

Here are some screenshots
file-sample_150kB.pdf

This is an extreme setting that I would probably never use (although I am new to KoReader and using an eReader this week for the first time after 10 years so I don't know how I will use it yet) but I see what you mean by part of the screen being under the bezel. I would say that in my device there is a bit more under the bezel in the right side than in the left side, and in some of my screenshots you can see that the m in "Ut ac lorem" in the very first line of that page, almost almost goes under the bezel to the point that my left eye can see the right side pixels of the "m" and the right eye might be missing the very last colum of pixels of that "m" if the screen is centered towards my face. However the rest of the sentences seem to finish 1 or more pixels more to the left side and it is not as tight.

EDIT:
I got a screenshot now also showing how it crops the top area, with that 0.0 margin. I would also say that is super tight in my device, in a way that if i have my eyes in the center of the screen at a reasonable distance I am in the limit of seeing all the pixels or maybe missing the very top pixel. To me it looks good like this (i can always apply more margin if I want it less tight)

[NiLuJe]

What's the full panel resolution supposed to be exactly? (So I can grok how much the viewport actually crops on the right & bottom ;)).

[diegopau]

According to the specifications of the device:
Display type E Ink Kaleido™ 3
Display resolution 1404 × 1872 (greyscale) 702 × 936 (color)
Display size 7.8'' (19.8 cm)

[NiLuJe]

Oh, so that's a fairly good chunk of cropping there.