lilypond-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Screenshots/PNG files in manuals


From: Phil Holmes
Subject: Re: Screenshots/PNG files in manuals
Date: Fri, 16 Aug 2013 12:15:21 +0100

----- Original Message ----- From: "David Kastrup" <address@hidden>
To: <address@hidden>
Sent: Friday, August 16, 2013 11:59 AM
Subject: Re: Screenshots/PNG files in manuals


"Phil Holmes" <address@hidden> writes:

----- Original Message ----- From: "Phil Holmes" <address@hidden>
To: "Devel" <address@hidden>
Sent: Thursday, August 15, 2013 4:31 PM
Subject: Screenshots/PNG files in manuals


As I said earlier, I'm working on the tutorial in the LM.  It uses
screenshots to show what users will see on the screen.  The versions
on the web are (as expected from a pixel-based system) fine.
However, the versions in the PDF docs are badly scaled and look
ugly.  It seems that this is generally tackled for images by making
them large and then constraining the width in the tex version of the
source (this is how it's done in the essay). I'm wondering if
there's a better way - is there a recommended pixel-per-inch setting
for image files that will end up in the PDFs?  I've looked on the
web and couldn't find anything, but am hoping someone will know.

I resorted to generating a number of pixel-constrained grids at
different PPI to try to work this out, and this is what I've found.

The main problem with screenshot-type images in the PDFs is that the
viewer program scales them badly on screen, and as a result they look
bad.  Printed output is far better.  However, if the resolution of a
screenshot is left at its default, then the image in the PDF is far
too big.  In my experiments, it appears that a setting of 120 pixels
per inch gives a good compromise between having an image large enough
to be legible, and allowing images of a reasonable pixel count.

I don't actually understand what you are trying to say here.  A screen
shot should always have one pixel per pixel, anything else does not make
sense.  You want to use PNG.

With 120 PPI, the maximum image size is just over 750 pixels.

The main problem is that you'll ultimately want the output to be
something like 100dpi or 150dpi in print.  _Exactly_ so.  So scaling to
a certain width is likely to be problematic.  You should figure out the
typical available width, pick a resolution, and then resize your window
to match the available width before doing the screen shot.  Then it's
best to specify the exact width when including the image, and center the
image in the available line width whatever it may be.

--
David Kastrup


What I'm trying to say is that screenshots, because of their inherent pixel-based resolution, need somewhat careful treatment to get the best looking image in the manuals. If you look at the current LM in the Windows section, you'll see that the screenshots are not well scaled. The attached image illustrates this. And if you're trying to use a screenshot to show information, it needs to be a sensible size to be legible. AFAIK you can't include an image in the docs with a pixel sized scaling, since the PDFs work in inches and cm, rather than pixels. So there needs to be some sort of selection of a PPI setting for these. Just setting them to an arbitrary number of inches/cm is worse than a specific PPI.

PNGs carry the PPI information - so if you scale the PNG to 120 PPI, the screenshots look good in the viewer and printed out. 150 PPI and the screenshots are too small. 100 PPI and with any sensible screenshot the image flows off the side of the screen.

--
Phil Holmes

Attachment: LMSShot.png
Description: PNG image


reply via email to

[Prev in Thread] Current Thread [Next in Thread]