How to convert all files (in different formats) in given folder to different file type

Question

I have a folder with many images from different types (png, jpg, jpeg, bmp, pdf), and I would like to convert them all into png (for instance) using imagemagick.

Is there a single command which can perform this? If not, what should I do instead?

Thanks.

Solution 1

Try the mogrify command:

mogrify -format png *.*

But be careful. Without the -format option, mogrify overwrites the original images. Make sure to read the documentation.

Solution 2

Although mogrify seems to do the job, I would like to show you how this can be done with multiple commands with convert from ImageMagick.

I think multiple commands are better, because the number of file types is supposedly quite small and you can better adjust it to your needs:

This command:

for file in *.xbm; do convert $file "`basename $file .xbm`.png"; done

will convert all .xbm files to .png while not touching the xbm files.

Then you can move all "converted" files:

mkdir converted
for file in *.xbm; do mv $file converted/; done

Solution 3

You can use convert command from ImageMagick package, e.g.

find . -maxdepth 1 \( -iname \*.png -o -iname \*.jpg -o -iname \*.jpeg -o -iname \*.bmp -o -iname \*.pdf \) -exec convert -verbose "{}" "DEST_DIR/{}.png" \;

Or if you've got all the files in the same directory, try the following simpler way:

convert '*.*' converted_%04d.png

Similar: How can I scale all images in a folder to the same width?

Comments

[Tal Galili]

Thanks. I get the following error massage: C:\Users\Tal\s>mogrify -format png . mogrify.exe: unable to open module file C:\Program Files (x86)\ImageMagick-6.8. 3-Q16\modules\coders\IM_MOD_RL_INI_.dll': No such file or directory @ warning/mo dule.c/GetMagickModulePath/683. mogrify.exe: no decode delegate for this image format desktop.ini' @ error/cons titute.c/ReadImage/550. (Is this simple to resolve?)

[nwellnhof]

That's because mogrify tries to convert the file desktop.ini which isn't an image file. You should only pass image files to mogrify. Either delete desktop.ini or change *.* to a wildcard that only matches the image files in your directory. You can also run the command several times for every file format: mogrify -format png *.jpg, mogrify -format png *.bmp, etc.

[nutty about natty]

I'd like to merge different image file types into a single *.pdf file. How to adapt your code to make that work?

[nutty about natty]

I guess I could revert to other tools like pdftk (e.g. by using pdftk *.pdf cat output combined.pdf), but would rather have a one-liner to get the whole job done...

[miro marchi]

If mogrify is used with the -format option, the file is not replaced, but a new one is saved with the new prefix.

[AnnanFay]

If mogrify is used with the -format option using the original file format it will still overwrite the original. Not sure if there's anyway to avoid this.

[jan-glx]

The current command does not work if the filename contains spaces. One way to fix this is for file in *.xbm; do convert "$file" "`basename \"$file\" .xbm`.png"; done but I have a feeling that bash offers a cleaner solution for this.