No Hinting: Ubuntu Mono rendering not crisp like DejaVu Sans Mono (screenshots provided)

[Josh Triplett]

I installed the Ubuntu Mono font, and changed gnome-terminal to use it, increasing the size by 1pt as suggested, which gave it similar metrics to DejaVu Sans Mono, my current terminal font. I immediately noticed that the font rendering appeared very blurry, not crisp like DejaVu Sans Mono. I'll attach screenshots of both to demonstrate.

I took both of the attached screenshots on exactly the same region of text, in the same terminal, changing only the selected font. I used 7pt DejaVu Sans Mono, 8pt Ubuntu Mono, both at 124dpi on a laptop screen. I suggest opening both screenshots in tabs or windows, to allow switching between them and comparing the same characters in each font. The screenshots also document precisely which version of the font I used. :)

In the screenshots, notice that the underscore in Ubuntu Mono has a faint grey line below it, as though the character wanted to use an extra fraction of a pixel vertically, whereas the same character in DejaVu Sans Mono uses a single line. Similarly, note the vertical strokes in most characters, the top horizontal stroke in the 'a' and '7', and most of the strokes in the 't' and 'f'.

(Attaching the first screenshot with this initial report; I'll attach the second screenshot in a subsequent comment.)

[Paul Sladen (sladen)]

Hello Josh. Thank you for the screenshots, it's always useful when somebody attaches a visual example of what they've spotted. The reason that it doesn't looking sharp, is because there's no hinting information … yet.

Currently Dalton Maag-font engineers Jason Campbell and Vincent Connare have been working on the Ubuntu Mono hinting, as noted in the update earlier at:

  https://design.canonical.com/2011/09/ubuntu-monospace-beta/

Hinting is a time-consuming (and optional) step at the end of font production to enable a human designer/engineer to give the computer "hints" about how to distort a glyph at a particular pixel size, such that the horizontal and vertical stems of the character will end up being fitted to the available grid of pixels.

It's not possible yet, because it hasn't been done. However, when the hinting has been finished it will be possible to render the sharp (distorted) forms that you're after seeing with your preferred rendering setup.

Is that a useful answer, is there anything I missed, or could try and address in more detail?

[Josh Triplett (joshtriplett)]

Hi Paul,

Thank you very much for your response; it answers all my questions. I'm familiar with font hinting, and I didn't realize that the current preview of Ubuntu Mono didn't have hinting yet; that certainly explains the issue I saw. Sorry that I didn't find the existing bug report; I must have missed the right set of keywords.

I provided the screenshots for exactly the reasons you mentioned; any kind of bug report on a work of design needs as much clarity as possible to minimize subjective interpretations or unclear terms. (You might actually consider adding a note to the pages pointing at the bug-tracking system for the font to explicitly suggest including a screenshot.)

I love the look of Ubuntu Mono so far, and I look forward to seeing a version with hinting.

On an unrelated note, the design.canonical.com page you linked to has a certificate error:
"The certificate expired on 08/17/11 04:32. The current time is 09/14/11 19:12."

Thanks,
Josh