Convert several files from a format to another:

$ convert img_*.bmp img_%04d.png

Resize images of the current folder to progressive jpeg. Resized images will not be greater than 600x600, but the aspect ratio will be respected:

$ convert -resize 600x600 -sharpen 1 -interlace Line ./* ./pict%04d.jpg

Reduce size of a PDF by limiting its images to 1000 pixels and convert its color-space to grayscale:

$ convert -resize 1000x1000 -type Grayscale ./big.pdf ./smaller.pdf

Assemble images vertically:

$ convert img1.jpg img2.jpg img3.jpg -append big.jpg

Assemble images horizontally:

$ convert img1.jpg img2.jpg img3.jpg +append big.jpg

Remove all whitespace (or any solid-color) surrounding the original.png image:

$ convert ./original.png -trim ./trimmed.png

Add a 5% white border around the image:

$ convert ./original.png -bordercolor White -border 5%x5% ./original-with-border.png

Same as above but with a deep black 5% border on the side and a total image height 3x times taller as the original:

$ convert ./original.png -bordercolor '#1a1a1a' -border 5%x100% ./original-with-border.png

Massive in-place optimization of all PNG images available in sub-directories:

$ find ./ -iname "*.png" -exec pngcrush "{}" "{}.crushed" \; -exec mv "{}.crushed" "{}" \;

Same as above, but remove all known chunks, those encoding color profiles, gamma and text, and only keeps transparency chunks:

$ find ./ -iname "*.png" -exec pngcrush -rem alla "{}" "{}.crushed" \; -exec mv "{}.crushed" "{}" \;

Lossless optimization of JPEG files:

$ find . -iname "*.jpg" -exec jpegtran -optimize -outfile "{}.optimized.jpeg" "{}" \;

Convert a PNG file to an optimized JPEG:

$ convert ./original.png TGA:- | cjpeg -optimize -progressive -quality 80 -outfile compressed-image.jpeg -targa

Same as above but as a loop for all PNG files in current folder:

$ for f in *.png; do convert "$f" TGA:- | cjpeg -optimize -progressive -quality 80 -outfile "$f.jpeg" -targa; done

Print all metadata of a video file:

$ exiftool ./MVI_4441.MOV
Audio Channels                  : 2
Compressor Version              : CanonAVC0002
Camera Model Name               : Canon EOS 7D
Firmware Version                : Firmware Version 2.0.3
Image Size                      : 1920x1080
Megapixels                      : 2.1
Avg Bitrate                     : 47.5 Mbps
(...)

Same as above but print the canonical ID of each field:

$ exiftool -short ./MVI_4441.MOV
AudioChannels                   : 2
CompressorVersion               : CanonAVC0002
Model                           : Canon EOS 7D
FirmwareVersion                 : Firmware Version 2.0.3
ImageSize                       : 1920x1080
Megapixels                      : 2.1
AvgBitrate                      : 47.5 Mbps
(...)

Print all metadata, with fields grouped by their family:

$ exiftool -groupHeadings MVI_4586.MOV
---- ExifTool ----
ExifTool Version Number         : 12.60
---- File ----
File Name                       : MVI_4586.MOV
File Type                       : MOV
File Type Extension             : mov
MIME Type                       : video/quicktime
---- QuickTime ----
Major Brand                     : Apple QuickTime (.MOV/QT)
Minor Version                   : 2007.9.0
Media Data Offset               : 32
Movie Header Version            : 0
(...)

Show all date fields with their canonical IDs, grouped by family:

$ exiftool -groupNames -short -'*Date' MVI_4586.MOV
[File]          FileModifyDate                  : 2023:06:03 17:14:28+04:00
[File]          FileAccessDate                  : 2023:06:03 21:36:26+04:00
[File]          FileInodeChangeDate             : 2023:06:03 18:55:28+04:00
[QuickTime]     CreateDate                      : 2015:09:26 14:44:10
[QuickTime]     ModifyDate                      : 2015:09:26 14:44:10
[QuickTime]     TrackCreateDate                 : 2015:09:26 14:44:10
[QuickTime]     TrackModifyDate                 : 2015:09:26 14:44:10
[QuickTime]     MediaCreateDate                 : 2015:09:26 14:44:10
[QuickTime]     MediaModifyDate                 : 2015:09:26 14:44:10

Copy the CreateDate field of the QuickTime family from a MVI_4586.MOV file to MVI_4586.mp4:

$ exiftool -tagsfromfile MVI_4586.MOV "-QuickTime:CreateDate" MVI_4586.mp4

Same as above but for all date fields:

$ exiftool -tagsfromfile MVI_4586.MOV "-QuickTime:*Date" MVI_4586.mp4

Transfer all *Date fields from all .MOV files of the current ./ directory to their corresponding .mp4 files:

$ exiftool -tagsfromfile %f.MOV "-QuickTime:*Date" -ext mp4 ./

Remove all metadata of a JPEG file:

$ exiftool -all= image.jpg

Prefix all JPEG filename with their EXIF date:

$ for i in *.jpg; do exiv2 -v -r '%Y%m%d_%H%M%S_:basename:' rename "$i"; done

Remove recursively (and in-place) the color profile and comments embedded in all PNG images:

$ mogrify -verbose -monitor -strip ./*.png

Export all videos from the 2012-12-32 - NYE album to the current folder, and download from iCloud the missing ones:

$ osxphotos export ./ --album "2012-12-32 - NYE" --download-missing --only-movies

Same as above but only for videos shot with a Canon camera and encoded with the CanonAVC0002 codec:

$ osxphotos export ./ --album "2012-12-32 - NYE" --download-missing --only-movies --exif CompressorVersion 'CanonAVC0002'

Export all videos from the Yearly archives/2014 subfolder while keeping the same folder structure:

$ osxphotos export ./ --regex "Yearly archives/2014" "{folder_album}" --download-missing --only-movies --directory "{folder_album}"