Fix embedded CMYK image

[zwaldowski]

Fixes two issues with the embedding of JPEG images in CMYK.

• Images would not be visible in the output document at all. This is because pdf-lib would give it the DeviceCYMK space, apparently a transposition. PDF 32000-1:2008, Section 8.6.3 confirms the spelling DeviceCMYK.
• Once they would appear, images would be inverted. This seems to be due to a difference between CMYK JPEG files on disk and streams in PDF. See code comment in PR for more detail (with one caveat).

Before

PDF
Input

After

PDF
Input

[Hopding]

This looks great. Thank you very much @zwaldowski!

P.S. I love the caveat meme. If we're honest, do any of us really have any idea what we're doing? 😂

[Hopding]

Version 1.5.0 is now published. It contains this fix. The full release notes are available here.

You can install this new version with npm:

npm install pdf-lib@1.5.0

It's also available on unpkg:

• https://unpkg.com/pdf-lib@1.5.0/dist/pdf-lib.js
• https://unpkg.com/pdf-lib@1.5.0/dist/pdf-lib.min.js

As well as jsDelivr:

• https://cdn.jsdelivr.net/npm/pdf-lib@1.5.0/dist/pdf-lib.js
• https://cdn.jsdelivr.net/npm/pdf-lib@1.5.0/dist/pdf-lib.min.js