Black text not visible on page in PDF

[ccisoc]

We have a PDF produced by our own application through our own pdf implementation. If we open a PDF with text using PDF.js the text is not visible. When I inspect the page I can see the text is present in the page source, but not present in the page view.

The same PDF does not have any issues in Adobe Acrobat, Apple Preview, Artifex Ghostscript, printers and RIPs. I tested it with newest version of of Firefox 32.0. It was also present in firefox 25.

Pdf is available here:
http://docdroid.net/hhoq

Screenshot of PDF open in Adobe Reader:

[yurydelendik]

Looking at the page content font size is set to 56234:

/F1 56234 Tf
100.000000 Tz
1.000000 0 0.000000 1.000000 537581 2550414 Tm 
1 Tw [(T) 89 (es) 19 (t T) 89 (e) 39 (xt)] TJ

We probably shall specify the max limit to the font size we use for canvas painting, similar with what we do for min font size.

[yurydelendik]

https://github.com/mozilla/pdf.js/blob/master/src/display/canvas.js#L28

Setting as a starter bug, just to verify if capping the font size to some reasonable number e.g. 64 will fix the issue.

[ccisoc]

You should look at bit more on the pdf. We do not use 1/72 inches as our units. We use 1/10000 mm because we need that preciseness. Hence at the start of the pdf we translate all units to this:

0.000283465 0 0 0.000283465 0 0 cm

That 56234 is translated to a normal font size of 16.

[yurydelendik]

Right, during painting to canvas we are trying to use the original font size e.g. ctx.fontStyle = "56234px f1"; in your case. We adjust the font size for really small fonts atm, but we should do that for really big fonts as well.

[ccisoc]

Arh okay. Will see if you are able to fix the bug.

[yurydelendik]

@ccisoc are you author of this PDF? can we use it in our reference tests?

[ccisoc]

@yurydelendik Yes you can say i am the author of the PDF. Unfortunately we embed a font from Ghostscript in the PDF which i do not know if we are allowed to distribute to other people than our customers and their customers. So on the grounds that i do not want to go through legal i'dd rather say no.

But i'll try to see if I can produce a similar PDF without an embedded font for you to use in reference tests.

[Snuffleupagus]

@ccisoc I've created a reduced test case for this issue, see PR #5443.