ImageSnap

by: Robert Harder (original), Swift port

Capture Images from the Command Line

ImageSnap is a command-line tool that lets you capture still images from an iSight or other video source. This is a Swift rewrite of the original Objective-C version, using modern AVFoundation APIs.

Installation

Building from Source

Using Xcode:

1. Open ImageSnap.xcodeproj in Xcode
2. Select Product > Build (⌘B)
3. The built imagesnap executable will be in the DerivedData folder

Using Command Line:

cd ImageSnap
xcodebuild -scheme imagesnap -configuration Release build

Or compile directly with swiftc:

swiftc -o imagesnap main.swift -framework AVFoundation -framework AppKit -framework CoreImage

Installing

Copy the imagesnap binary to someplace on your path like /usr/local/bin:

cp imagesnap /usr/local/bin/

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

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 "FaceTime HD Camera"..................snapshot.jpg

To specify a filename, make that your last argument:

$ imagesnap icu.jpg
Capturing image from device "FaceTime HD Camera"..................icu.jpg

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

$ imagesnap -l
Video Devices:
=> FaceTime HD Camera
=> Logitech BRIO
=> USB 2.0 Camera

To select a specific video device use the -d 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 every 60 seconds:

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

Use -n to limit the number of timelapse captures:

$ imagesnap -t 10 -n 5
Capturing image from device "FaceTime HD Camera"..................snapshot-00001.jpg
snapshot-00002.jpg
snapshot-00003.jpg
snapshot-00004.jpg
snapshot-00005.jpg

There is a default warmup period of three seconds 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 -w 0
Capturing image from device "FaceTime HD Camera"...snapshot.jpg

Command Line Options

USAGE: imagesnap [options] [filename]
Version: 0.3.0
Captures an image from a video device and saves it in a file.
If no device is specified, the system default will be used.
If no filename is specified, snapshot.jpg will be used.
Supported image types: JPEG, TIFF, PNG, GIF, BMP

  -h          This help message
  -v          Verbose mode
  -l          List available video devices
  -t x.xx     Take a picture every x.xx seconds
  -n x        Limit the number of timelapse pictures to x
  -q          Quiet mode. Do not output any text
  -w x.xx     Warmup. Delay snapshot x.xx seconds after turning on camera
  -d device   Use named video device

Image Formats

The following image formats are supported and are determined by the filename extension:

• JPEG (.jpg, .jpeg) - default
• PNG (.png)
• TIFF (.tiff, .tif)
• GIF (.gif)
• BMP (.bmp)

Changes

• v0.3.0 - Complete rewrite in Swift using AVFoundation. Supports macOS 13+.

Requirements

• macOS 13.0 (Ventura) or later
• Xcode 15.0 or later (for building)
• A connected camera (built-in or external)

Old Versions

If you want the old Objective-C version of this tool, you can grab that from the releases section or use git to grab the old repo.

You can grab it like so:

git checkout v0.2.16

I did a complete rewrite in Swift, but that brings the compatibility down, or up depending on how you count, to only work on later versions of MacOS. The previous Objective-C version goes way back, and XCode complains about old frameworks.

I'm kind of leaning toward going back to the Objective-C version so that people with older MacBooks and what not can still use this tool. If this is causing you problems, please let me know.

License

Public Domain - This software is released into the Public Domain. You can do whatever you want with it.