Imagemagick is a wonderful tool if you want to do batch image processing.
There are few operations which are very useful, but I tend to forget them all the time. :P
Image resizing:
$mogrify -resize HxW *.jpg
where, HxW is image size (Height x Width). We can take any image format in place of jpg.
If we want to force the desired size,
$mogrify -resize HxW! *.jpg
I prefer using the second command to the first one.
Remember, this replaces the original image file. So you need to take a backup of the current image directory before applying this command.
Format Converstion:
For conversion of all images in current directory to another format,
$mogrify -format <newformat> *.<currentformat>
for example,
$mogrify -format ppm *.bmp
This converts all bmp images to ppm format and saves a copy.
We can apply this command without worrying at all, since a new copy is created without losing original image format.
Autocrop Images:
Usually when we save matlab figures, we get large undesirable white boundaries. We may want to crop those images to fit to actual image dimensions.
$convert -trim image.jpg image.jpg
For processing images in a batch, you can use the following script:
$for i in `ls *.jpg`; do convert $i -trim `basename $i`; done
If you do not want to replace the current image, and rather make a new copy of it, do as follows:
$for i in `ls *.jpg`; do convert $i -trim cropped_`basename $i`; done
Refer this link to go through more complicated settings for the same purpose.
There are few operations which are very useful, but I tend to forget them all the time. :P
Image resizing:
$mogrify -resize HxW *.jpg
where, HxW is image size (Height x Width). We can take any image format in place of jpg.
If we want to force the desired size,
$mogrify -resize HxW! *.jpg
I prefer using the second command to the first one.
Remember, this replaces the original image file. So you need to take a backup of the current image directory before applying this command.
Format Converstion:
For conversion of all images in current directory to another format,
$mogrify -format <newformat> *.<currentformat>
for example,
$mogrify -format ppm *.bmp
This converts all bmp images to ppm format and saves a copy.
We can apply this command without worrying at all, since a new copy is created without losing original image format.
Autocrop Images:
Usually when we save matlab figures, we get large undesirable white boundaries. We may want to crop those images to fit to actual image dimensions.
$convert -trim image.jpg image.jpg
For processing images in a batch, you can use the following script:
$for i in `ls *.jpg`; do convert $i -trim `basename $i`; done
If you do not want to replace the current image, and rather make a new copy of it, do as follows:
$for i in `ls *.jpg`; do convert $i -trim cropped_`basename $i`; done
Refer this link to go through more complicated settings for the same purpose.
