Image Snap

by: Robert Harder

Capture Images from the Command Line

ImageSnap is a Public Domain command-line tool that lets you capture still images from an iSight or other video source.

Installation

ImageSnap is included in various package managers such as Homebrew and MacPorts. The easiest way to install imagesnap is probably with one of those commands such as brew install imagesnap.

You can also simply copy the binary imagesnap file to someplace on your path like /usr/local/bin, or leave it in a "current directory," and call it with ./imagesnap instead. If your download has a version number appended to it like imagesnap-0.2.10 then I recommend you rename it to just imagesnap.

The first time you use the tool, you may get a popup window from MacOS asking to give imagesnap permission to access the camera.

Enjoy!

Usage

To capture an image simply run the program from the command line. There is a delay of a few seconds while the camera warms up, and then...snap!

$ imagesnap
Capturing image from device "iSight"..................snapshot.jpg

To specify a filename, make that your last argument:

$ imagesnap icu.jpg
Capturing image from device "FaceTime HD Camera (Built-in)"..................icu.jpg

If you have multiple video devices attached to your computer, use the -l ("el") flag to list them:

$ imagesnap -l
Video Devices:
=> EpocCam
=> OBS Virtual Camera
=> Logitech BRIO
=> FaceTime HD Camera (Built-in)
=> USB 2.0 Camera

To select a specific video device use the -d device flag with the full or partial name of a device:

$ imagesnap -d BRIO
Capturing image from device "Logitech BRIO"..................snapshot.jpg

You can capture a series of images in a timelapse using the -t option.
The following command would take a picture ever 60 seconds:

$ imagesnap -d BRIO -t 60
Capturing image from device "Logitech BRIO"..................snapshot-00001.jpg
snapshot-00002.jpg
snapshot-00003.jpg

There is a default warmup period of three seconds (new to version 0.2.13) when you take a picture. This gives the camera time to get its sensors all set up. Your camera might have a faster or slower response time, so you can adjust the warmup period to suit your needs.

$ imagesnap -d BRIO -w 0
Capturing image from device "Logitech BRIO"..................snapshot.jpg

Image Formats

Only JPEG output is supported.

Changes

v0.2.16 - Added ability to specify directory where timelapse images will be saved.
v0.2.15 - Added -n flag to limit the number of timelapse pictures. Also changed first timelapse image numbering to start at one instead of zero.
v0.2.14 - Bump to fix distribution problems only
v0.2.13 - Default warmup period is now three seconds. Set -w 0 if you want no delay.
v0.2.12 - Supports native M1. Other tweaks for package managers.
v0.2.11 - Some documentation updates and preparing for better integration with package managers like Homebrew and MacPorts
v0.2.10 - Fixed bug when showing Capturing image with xxx...snapshot.jpg
v0.2.9 - When doing timelapse, sequence numbers will pick up where the last filename left off.
v0.2.8 - Removed timestamp from filename when doing sequence of images with -t option
v0.2.7 - When specifying a device with the -d flag, substrings are matched if an exact match is not found. Some cleanup in the code for modern Xcode versions. Verified on Mojave and Big Sur
v0.2.6 - Unknown point release four years before v0.2.7 - I don't know what it was.
v0.2.5 - Added option to delay the first snapshot for some time. Added a time-lapse feature (thanks, Bas Zoetekouw).
v0.2.4 - Found bug that caused crash on Mac OS X 10.5 (but not 10.6).
v0.2.4beta - Tracking bug that causes crash on Mac OS X 10.5 (but not 10.6).
v0.2.3 - Fixed bug that caused all images to be saved as TIFF. Not sure when this bug was introduced.
v0.2.2 - Added ability to output jpeg to standard out. Made executable lowercase imagesnap.
v0.2.1 - Changed name from ImageCapture to ImageSnap to avoid confusion with Apple's Image Capture application.
v0.2 - Multiple file formats (not just TIFF). Faster response.
v0.1 - This is the initial release.

A Note About Public Domain

I have released this software into the Public Domain. That means you can do whatever you want with it. Really. You don't have to match it up with any other open source license — just use it. You can rename the files, do whatever you want. If your lawyers say you have to have a license, contact me, and I'll make a special release to you under whatever reasonable license you desire: MIT, BSD, GPL, whatever.