How to take a high quality screenshot of the whole page in Firefox using GCLI?

Solution 1:

Finally, I found the answer to my question. I 'd love to answer my questions.

First of all, where the credit due; Eric's Archived Thoughts, I found this tutorial accidentally.

The answer is simple, just add a --dpr option/argument to the command with the relative pixel resolution to the normal. Say, for example, to capture at 4 times the resolution of the normal resolution put --dpr 4, note that there's a space before the number. You may also use numbers with decimal parts like 5.3, 5.6 etc. An example command may look like:

screenshot filename.png --dpr x

That's all.

And of course, there's improvement in the quality of the screenshots.

Example screenshots:

At normal resolution

At 5x resolution