Autoexif NPM | npm.io

autoexif

A specialized command-line utility that declutters EXIF metadata in digital images by preserving only the essential technical parameters while removing extraneous information about camera equipment, software, and other non-essential details.

Overview

Digital photographs typically contain extensive embedded metadata (EXIF data) that includes numerous parameters, many of which are irrelevant to the actual photographic qualities of the image. This metadata often contains camera and lens model information that can introduce bias when evaluating image quality.

Autoexif creates a clean copy of your original image with only essential technical metadata intact—preserving information valuable for understanding the photographic conditions while eliminating equipment-specific details and other extraneous information that clutters the metadata profile.

Key Features

Creates a non-destructive workflow by always generating a separate output file, never modifying the original
Completely removes all embedded metadata from the image copy
Selectively restores only specific technical metadata elements that directly relate to the photographic parameters
Eliminates equipment-specific information that could introduce bias when evaluating image quality
Offers flexible output options, with automatic generation of output filenames if not specified

Installation

Prerequisites

Node.js 18 or higher
npm

Installation Steps

npm i -g autoexif

Usage

Basic Usage

# Process a single image
autoexif --input path/to/image.jpg

# Specify an output path
autoexif --input path/to/image.jpg --output path/to/output.jpg

# Using shorthand options
autoexif -i path/to/image.jpg -o path/to/output.jpg

Options

-i, --input <path> - Path to the input image file (required)
-o, --output <path> - Path for the output file (optional)
--version - Display the version number
--help - Show help information

If no output path is specified, the program will create a new file in the same directory as the input file with .out inserted before the extension (e.g., image.jpg becomes image.out.jpg).

Preserved Metadata

Autoexif preserves a carefully curated set of non-identifying technical information, including:

Exposure Information

Exposure time, aperture (F-number), ISO
Exposure program, mode, and compensation
Metering mode
Brightness, shutter speed values

Optical Information

Focal length (including 35mm equivalent)
Field of view, circle of confusion
Hyperfocal distance
Digital zoom ratio

Image Properties

Color space, temperature, white balance
Contrast, saturation, and sharpness settings
Image dimensions and resolution
Orientation

Scene Information

Scene type and capture mode
Light source and value
Flash information

Use Cases

Autoexif is particularly valuable for:

Photographers sharing work for technical feedback without equipment bias influencing the critique
Photography educators focusing discussions on exposure, composition, and technique rather than gear
Photography forums where equipment discussions can detract from image quality conversations
Creating cleaner, more focused image metadata profiles for archiving
Removing extraneous editing software information and revision history while keeping essential parameters
Sharing images with reduced metadata clutter (with privacy improvement as a secondary benefit)

Examples

Basic Example

autoexif -i vacation.jpg

Creates vacation.out.jpg with identifying metadata removed.

Processing with Custom Output

autoexif -i family-photo.jpg -o family-photo-clean.jpg

Processes family-photo.jpg and saves the cleaned version as family-photo-clean.jpg.

Implementation

The tool leverages the robust ExifTool library (via exiftool-vendored) to handle the complex metadata structures found in modern image files. The process follows a methodical approach of copying, clearing, and selectively restoring specific metadata elements to ensure consistent results across different image formats and sources.

By focusing exclusively on the technical parameters that matter for photographic analysis, autoexif provides a streamlined approach that preserves valuable image context while removing equipment-specific information that can introduce bias or unnecessary clutter in the metadata profile.