Screenshots into b&w LaTeX Figures

June 29, 2008 3:30 PM

How do I best prepare color .png screenshots for publication as figures in a LaTeX document that will be printed in b&w conference proceedings?

My paper includes several color screenshots from an application I'm building. I've captured the screenshots using OS X's Grab feature (cmd+shift+4) and converted them to EPS3 using ImageMagick's convert commandline tool (convert figure.png eps3:figure.eps) and successfully inserted the figures into my LaTeX document, which renders legibly using pdflatex.

Concerns: I'm fairly certain that the conference proceedings will be printed in b&w; my screenshots are color. I presume I'm going to have to convert them to halftone (probably in Photoshop, since I imagine I'll have to rescale them anyway). Is it safe to assume 300dpi?

Rendering halftones implies that the images will have to be printed actual size; what's the best way to ensure this when marking up an \includefigure{} in LaTeX? I know specifying no height or width will render the image in its native height and width, but is that height and width in pixels or inches? How do I prevent rescaling that will mess up the halftones for the printer?

Right now I'm using the subfigure package and printing two figures side by side on the page with \includefigure[height=.45\textwidth]. How can I cause LaTeX to output this width, so I can manually resize the screenshots before converting them to b&w?

What's the best way to preview this output? I have access to a color laser printer; will it render the halftoned images approximately as they will appear in print or should I try something else?

posted by Alterscape to computers & internet (4 comments total)

Can you talk to someone at the conference? They should have instructions on how to do this.
posted by null terminated at 5:04 PM on June 29, 2008

You can use png directly in LaTeX if you're using pdflatex. I agree with null terminated, if you have questions about preparing a print-ready pdf, talk to the people who will be printing the pdf.
posted by demiurge at 5:12 PM on June 29, 2008

I think it's probably better to let the printer do the halftoning. (PostScript has always supported halftones, even before it supported color, so I think it's likely that the final RIP would do a good job on your image, better than you can without knowing anything about the physical printing apparatus.) You might want to do the conversion to grayscale yourself, though, to make sure it's legible (e.g., two distinct colors coming out indistinguishable shades of gray, that kind of thing).
posted by hattifattener at 5:19 PM on June 29, 2008

I know nothing about LaTeX, but I do know about printing.

My experience is that you are better off making your images look as good as possible yourself; most folks who do digital printing for conferences, etc., are less invested in the quality of the end result than a Kinko's worker would be.

A screenshot will be 72 ppi (pixels per inch). Optimal print resolution is 300 ppi. This is why screenshots in a printed document often look illegibly bad. (For laser/office printing you can get away with 200 or even 150 ppi if you must.)

My advice:

open your screenshots in Photoshop.

image > image resize:check constrain proportions, uncheck resample. Enter 300 in the resolution field. (The physical dimensions of your image will be ~25% of what they were, but the overall file size will be the same.)

image > mode > grayscale

your images may look a little flat and dull. if so:

image > adjustments > brightness/contrast (just play with the sliders till things looks a little better, crisper. +5 to +30 is about the usual useful range.)

save as with BW or something in the title. If you have a bunch, you might want to record and action. Use them in LaTeX at 100% of the new size.


image > adjustment >
posted by Cranialtorque at 7:56 PM on June 29, 2008