More contrast / darker text?

[GoogleCodeExporter]

Thank you for a fabulous PDF reader with so many features, fast and open source.

However, I just have one more question. It's about the rendering of text. I've 
noticed that my PDF documents appear more "gray"/lighter compared to some other 
readers for Android. Somewhat lack of contrast. I've tried adjusting contrast 
and exposure in book settings, but results are not that good. Increasing the 
contrast eventually makes the text unreadable.

For illustration, I took two screenshots. One of a page in EBookDroid (default 
rendering settings), one from another reader. If you zoom the pictures to 100%, 
you can see that the formulas and text appear somewhat more clear (more black, 
more contrast) in the "other_reader.png" compared to the text in 
"ebookdroid.png". 

My question is: Would it be possible to render the text with more contrast? 
Because as said, adjusting the contrast in book settings to for instance 120 
will make the text look bad, like shown in the 3rd screenshot. This 'problem' 
might seem trivial, but it's actually affect the readability.

Thanks again for a great reader - best one out there :)

Original issue reported on code.google.com by johnthor...@gmail.com on 6 Dec 2012 at 3:14

Attachments:

• ebookdroid.png
• other_pdf_reader.png
• contrast_120.png

[GoogleCodeExporter]

Actually library that we are using for rendering (MuPDF) do not provide much 
settings for rendering quality. All postprocessing are performed on decoded and 
rendered picture and mainly targeted for full-page scan documents. I'll try to 
find if there is some possibility to interfere internal MuPDF behaviour.

Original comment by Andrei.K...@gmail.com on 6 Dec 2012 at 4:10

• Changed state: Discussion

[GoogleCodeExporter]

Original comment by Andrei.K...@gmail.com on 6 Dec 2012 at 4:10

• Added labels: Type-Enhancement
• Removed labels: Type-Defect

[GoogleCodeExporter]

I see :) I think MuPDF is a great choice and I've seen it being used in many 
open source projects. Very snappy performance :) Fortunately this rendering 
"problem" is really not a big issue, but if you found anything which could help 
make the text look better I would really appreciate it. 

Thank you for very fast developer response. The app/reader is really good. Open 
Source makes it even better.

Original comment by johnthor...@gmail.com on 6 Dec 2012 at 6:54

[GoogleCodeExporter]

Just one more thing. I'm using a 3rd-party PDF reader on my Kindle, and it uses 
MuPDF for rendering. It has the choice of choosing a contrast between 
"lightest, lighter, normal, darker, darkest". Works really well and produces 
fine results. You can find the project here: 
https://github.com/chrox/kindlepdfviewer

Not sure if you can find anything useful there if you haven't tried it 
yourself. I would be glad to help and contribute if there's some need.

Original comment by johnthor...@gmail.com on 6 Dec 2012 at 8:51

[GoogleCodeExporter]

Along with Contrast setting I added Gamma correction setting. I think it will 
suite more for gray-scale images.

Original comment by Andrei.K...@gmail.com on 7 Dec 2012 at 10:34

• Changed state: Fixed

[GoogleCodeExporter]

I just tried your 1.6.3 version. The gamma correction setting works perfect! 
Text looks so much better now and readability has improved significantly. 

Thank you so much.

Original comment by johnthor...@gmail.com on 15 Dec 2012 at 1:24