Converting multiple image files from JPEG to PDF format

Question

I want to convert some files from jpeg to pdf. I am using following command.

$ convert image1.jpg image1.pdf 

But I have 100 images. How should I convert all of them to corresponding pdfs?

I tried

$ convert image*.jpg image*.pdf 

It doesn't work.

Answer 1

In bash:

for f in *.jpg; do
  convert ./"$f" ./"${f%.jpg}.pdf"
done

Answer 2

You can use the mogrify command for this. Normally, it modifies files in-place, but when converting formats, it writes a new file (just changing the extension to match the new format). Thus:

mogrify -format pdf -- *.jpg

(Like enzotib's ./*.jpg, the -- prevents any strange filenames from being interpreted as switches. Most commands recognize -- to mean "stop looking for options at this point".)

Answer 3

faster but unusual syntax:

parallel convert '{} {.}.pdf' ::: *.jpg

Runs in parallel (using https://www.gnu.org/software/parallel/). I haven't noticed any multi-threading in convert yet, which would limit the effective parallelization. If that is your concern, see in the comment below for a method to ensure no multi-threading occurs.

Answer 4

https://gitlab.mister-muffin.de/josch/img2pdf

In all of the proposed solutions involving ImageMagick, the JPEG data gets fully decoded and re-encoded. This results in generation loss, as well as performance "ten to hundred" times worse than img2pdf.

Available in Debian since Debian 9 (stretch) and Ubuntu since 16.04 (xenial). Also can be installed with pip img2pdf provided you have dependencies (e.g. apt-get install python python-pil python-setuptools libjpeg-dev or yum install python python-pillow python-setuptools).

Answer 5

Here is a way that combines the best of the above suggestions into a simple, efficient, robust command line:

find /path/to/files -iname '*.jpg' -exec mogrify -format pdf {} +

It works fine with filenames that begin with a - or contain spaces. Note the use of -iname which is the case-insensitive version of -name so it will work on .JPG just as well as .jpg.

This uses find to get the file list instead of shell globbing with the *.jpg wildcard which can result in an 'Argument list too long' error on some systems. Though as @enzotib points in a comment, behavior of using globbing in a for loop is different than for a command's arguments.

Also, find will handle subdirectories, whereas shell globbing will not unless you happen to have shell-specific features like the **/*jpg recursive globbing syntax in zsh.

EDIT: I thought I would add another useful feature of find that I thought of after reading a comment by @IlmariKaronen about re-running the command and only converting files that have changed since the first run.

On the first pass you can touch a timestamp file after the convert is finished.

find /path/to/files -iname '*.jpg' -exec mogrify -format pdf {} +; touch timestamp

Then add -newer timestamp to the find expression to operate on the subset of files whose last-modified time is newer than the timestamp file. Continue updating the timestamp file after each run.

find /path/to/files -iname '*.jpg' -newer timestamp -exec mogrify -format pdf {} +; touch timestamp

This is an easy way to avoid having to resort to a Makefile (unless you're already using one) and it is another good reason why it is worth using find whenever possible... it has versatile expressiveness while remaining concise.

Answer 6

You can do this with convert directly. This is to be found at the bottom of ImageMagicks Site about Command Line Processing.

convert *.jpg +adjoin page-%d.pdf

Answer 7

I've used the following makefile for something similar:

SVG = $(wildcard origs/*.svg)
PNG = $(patsubst origs/%.svg,%.png,$(SVG))

all: $(PNG)

%.png: origs/%.svg
    convert -resize "64x" $< $@


clean: 
    rm $(PNG)

Now I can just run make and I get png files for every svg file that lies around.

Edit

As requested:

• wildcards generates a list of all svgs in origs/
• pathsubst takes this list and produces a list of png file names (different folder and extension. Example: origs/foo.svg becomes foo.png)
• Rule 1: all: $(PNG) defines, that the target "all" depends on all PNGs
• Rule 2: %.png: origs/%.svg defines, thethe file $X.png depends on origs/$X.svg and can be generated by calling convert ... $< $@.
  • $< is the dependency and and
  • $@ is the target name
• RUle 3: is just for cleaning up

Answer 8

If you use only image files than maybe you would like to use Comic Book Archive (.cbr, .cbz, .cbt, .cba, .cb7)

• If you use 7Z then rename the file extension (suffix) to .cb7
• If you use ACE then rename the file extension (suffix) to .cba
• If you use RAR then rename the file extension (suffix) to .cbr
• If you use TAR then rename the file extension (suffix) to .cbt
• If you use ZIP then rename the file extension (suffix) to .cbz

This is much more flexible than PDF.

Under Linux you can use software like Comix, Evince, Okular and QComicBook.

https://secure.wikimedia.org/wikipedia/en/wiki/Comic_book_archive

Answer 9

A tiny script would do the trick. (tested with ksh88 on Solaris 10)

script.ksh

#!/bin/ksh

[[ $# != 1 ]] && exit 255 # test for nr of args

pdfname=$(sed -e 's/\(.*\)\.jpg/\1\.pdf/' <(echo $"1")) #replace *.jpg with *.pdf
convert "$1" $pdfname

Then you can run find to execute the script:

find dir -name image\*.jpg -exec /bin/ksh script.ksh {} \;

Note that both script.ksh and the find command I gave you, might have different syntaxes depeding on the OS and the shell you are using.

Answer 10

The MacOS utility SIPS  Under MacOS (Sierra), Apple's built-in command-line utility sips provides comprehensive access to all of Apple's raster-image utilities; this turns out to include the conversion of jpg to pdf.

For example, from an existing low-resolution/small-size jpg image 'cat.jpg' (of size 8401 bytes), the following command-line creates 'cat.pdf', with no change in raster-resolution and minimal expansion of file size:

$ sips -s format pdf cat.jpg --out 'cat.pdf' 1>/dev/null 2>&1
$ ls -l cat.*
-rw-r--r--@ 1 <user redacted> <group redacted>  8401 Jun 18 07:06 cat.jpg
-rw-r--r--+ 1 <user redacted> <group redacted> 10193 Jun 18 07:22 cat.pdf

Conversion to Adobe's PSD raster-image format  A similar sips idiom creates Adobe-compatible *.psd files

$ sips -s format psd cat.jpg --out 'cat.psd' 1>/dev/null 2>&1
$ ls -l cat.jpg cat.psd
-rw-r--r--@ 1 Administration  staff    8401 Jun 18 07:06 cat.jpg
-rw-r--r--+ 1 Administration  staff  350252 Jun 18 07:37 cat.psd

Note however the 30-fold file-size expansion that is attendant to the use of the Adope psd raster-format.

Book Production  In doing large-scale book production, involving hundreds of images, that are supplied in multiple formats, for me a convenient command-line idiom has been use ImageMagick utilities to create pure raster-image files in png format (with all meta-data and color profiles stripped-out), then use sips to restore a uniform set of color profiles and/or comments, and use sips also to generate final output files (most commonly *.png, *.psd, or *.pdf files).

Answer 11

Unfortunately convert changes the image before so to have minimal loss of quality of the original jpg you need to use img2pdf, I use this commands:

1) This to make a pdf file out of every jpg image without loss of either resolution or quality:

ls -1 ./*jpg | xargs -L1 -I {} img2pdf {} -o {}.pdf

2) This to concatenate the pdfpages into one:

pdftk *.pdf cat output combined.pdf

3) And last I add an OCRed text layer that doesn't change the quality of the scan in the pdfs so they can be searchable:

pypdfocr combined.pdf  

Answer 12

I got solve with imagemagick for conversion and parallel to accelerate my conversion process:

ls *.JPEG |parallel convert -density 200 -resize 496X646 -quality 100 {}  ../{.}.PDF

Answer 13

One of the simplest way to convert multiple files is to go to the file directory in linux terminal and type:

$ convert *.png mypdf.pdf