Export size & resolution

Software darktable
1

DT 3.6.0 on Manjaro

I’m trying to create a small booklet. I’m using lualatex for create the pdf file. I need 4 inch tall images.

At 300dpi x4" = 1200

but the text is 96dpi.

How do I figure out what file size should I export?

Thank you

2

The text of what?

3

use Scribus to layout the booklet or set the text as actual text and not an image in lualatex

4

I’m generating a pdf with left page: text, right page photo.

I’m using latex because I will have to doing many times exactly the same format for booklets but with different images and text.

Thanks

5

Is the 96dpi not just for the screen rendering…I think when you print it it will be rasterized and output at your print resolution?? I could be wrong

6

96DPI for text is likely just for rendering it to the screen. You should tell latex to embed fonts and you should be fine.

7

To make things a bit more clear: Modern LaTeX systems are not rendering the text as bitmap but as references to the embedded fonts when outputting to ps or pdf. If you have to deal with rasterized text there is probably something wrong in your installation or with your document. If you can post an example document (just the minimum necessary part to reproduce the issue), I could maybe help you to get it working.

About the picture size*, it will typically not be changed by LaTeX. Pictures are embedded as they are, dpi in the metadata are not important if you set the picture size in the code. You can therefore just use absolute pixel dimensions as you wrote above (1200 px for the example edge).

Edit: *Size means pixel dimensions here. Size of am image on the page is typically best determined in the LaTeX code, as the picture size cannot be determined reliably from the picture metadata as TeX is dpi agnostic regarding output unless you have very special circumstances.

8

As Chris said, lualatex generates PDF, and the embedded text is in vector form, so it’s size is DPI independent.
If you add the images with sizes in physical measures, they will be stretched or shrink to match, independently of the actual DPI.
Maybe share us some actual LaTeX code to help you ?

9 
\documentclass[notitlepage]{book}
\usepackage[paperheight=5.5in,paperwidth=8.5in,top=50pt,bottom=70pt,left=50pt,right=50pt]{geometry}
\usepackage{fontspec}
\defaultfontfeatures{Mapping=tex-text,Scale=MatchLowercase}
\usepackage[scaled=1.42]{helvet}	%% base size 14pt (numbus sans)%%
\usepackage[T1]{fontenc}
\linespread{1.68}
\renewcommand*\familydefault{\sfdefault}
\usepackage{fancyhdr}
\usepackage{microtype}

%% Spacing Between Paragraphs
\usepackage{parskip}
\setlength{\parskip}{6pt}
\parindent = 0.0in

\usepackage{graphicx}
\usepackage[export]{adjustbox}
\usepackage{lipsum} 

\begin{document}

\pagestyle{fancyplain}
\fancyhf{}
\renewcommand{\headrulewidth}{0pt}
\renewcommand{\footrulewidth}{1pt}
\lfoot{ \fancyplain{}{left foot} }
\rfoot{ \fancyplain{}{right foot} }
\pagenumbering{gobble}

\vspace*{20px}
\begin{center}
{\bfseries\Huge Main Title}\\[1cm]
{\scshape\LARGE Main Author}\\[1.5cm]
\end{center}

\newpage
\begin{center}
\section*{Bear: A Chow Chow}
\end{center}
\lipsum[1-2]
\newpage
{\centering
   \includegraphics[height=\textheight,keepaspectratio]{bear-01.jpg}
   \par
}
 
%% a lot more sections like this one

\end{document}
10

Why do you define the height of your picture as \textheight when you said you want pictures of 4" high?
Afaik, (Lua)LaTeX will do exactly as you ask… I’d expect your command to reserve a space of height \textheight (~27 pt? or ~.3") , with a width appropriate to the picture, and the picture scaled to fill that exact space.
If you want pictures of 4" high, tell LaTeX that:
\includegraphics[height=4in,keepaspectratio]{bear-01.jpg}

11

I know that latex does exactly what I asked for. That doesn’t mean that I know what I asked…

I think that during my many iterations that I already asked for a height of 4" but it wasn’t working correctly so I ended up with \textheight

Thanks

12

I think that with a 5.5in page height, and a bunch of margins and text, having a picture of 4in may overflow the page and make strange results; while the textheight one reduces the problem.
And to answer your initial question, here everything is measured as inches and points, so your text will be scaled to 300dpi by the pdf interpreter when printed.

13

SOLVED:

  1. By making sure that the fonts are included in the pdf.
  2. Image size: luatex produces a log file that shows the exact dimension in points.
(luatex.def)             Requested size: 263.25398pt x 263.25862pt.

and 72.27 pt = 1 inch * 300 pixels / inch ==> export size

Thank you

1 Like