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mozilla / pdf.js

PDF Reader in JavaScript
https://mozilla.github.io/pdf.js/
Apache License 2.0
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PDF.js version 2.1.266 displaying text of a PDF file not as sharp as Adobe Acrobat. #10783

Open kwank555 opened 5 years ago

kwank555 commented 5 years ago

Attach (recommended) or Link to PDF file here: Problematic file will be uploaded after ticket is created.

Configuration:

Steps to reproduce the problem:

  1. Open the problematic file in PDF.js
  2. Open the same problematic file in Adobe Acrobat Pro DC (version 2015.006.30482 used) or Adobe Reader

What is the expected behavior? (add screenshot) Text of the file should be sharp and readable.

What went wrong? (add screenshot) PDF.js displayed the text fuzzy while Adobe Acrobat DC displayed the text sharp.

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

namedoc commented 5 years ago

Here is a sample file:

Blurry_TestFile.pdf

THausherr commented 5 years ago

Your "text" is really a poorly scanned image.

kwank555 commented 5 years ago

@THausherr Thank you for your quick response. One question: Do you think Adobe Acrobat is doing something different so as to render Blurry_TestFile.pdf more sharply than PDF.js? Is it possible to make PDF.js match what Adobe Acrobat does in this aspect?

THausherr commented 5 years ago

I'm neither a developer for Adobe nor for PDF.js. Image scaling / interpolation / soft clipping is a complex topic. I looked at your image with Adobe Reader and IMHO it wasn't that good, and only slightly better than the rendering with PDF.js.

menver commented 5 years ago

Hello, Looked at this issue and the png provided from pdf.js is much worse then the document in Adobe. It is hard to read compared to adobe. I agree that the document is not great but is readable. FYI looking in Chome the png is very close to adobe as it is compensating for the quality. FF and IE both look bad. Image viewer (infranview or window image viewer) look bad.

DNWEIJ commented 2 years ago

Hello,

I have the same issue. Used the latest version of PDF.js 2.10 The image isn't a great scan, but can be read in chrome pdf good enough. In pdf.js the text isn't readable at all..... Are there maybe some tweak settings that can be made via config or something for PDF.js to improve the readability? image