image-js

Image processing and manipulation in JavaScript.

API Documentation

Installation

$ npm install image-js

Features

Supported image formats

The following formats can be loaded by image-js:

• PNG (8 or 16 bits, color or greyscale, with or without alpha)
• JPEG
• TIFF (8 or 16 bits, greyscale)

The following formats can be saved by image-js:

• PNG (8 or 16 bits)
• JPEG
• BMP (black and white)

Native support for various bit depths and image kinds

image-js was developed to be used in scientific applications where we often have to work on images that have more that 8 bits per channel.
Unlike many other libraries, if a 16-bit greyscale PNG is decoded, the resulting image has only one 16-bit channel and no pixel information is lost.

image-js can work with images that have 1 (binary), 8, 16 or 32 bits per channel.
It can accept an arbitrary amount of color channels (usually 1 or 3) and can handle an additional alpha component.

Basic image manipulation

image-js can be used to do simple image manipulations such as:

• Resize
• Crop
• Rotate
• Convert to greyscale
• Invert colors
• Gaussian blur
• Extract individual channels (red, green or blue)
• And more...

Statistics

image-js implements a number of functions to get statistics about an image:

• Histogram
• Max, min, median value
• And more ...

Advanced features for computer vision

• Image thresholding (otsu, triangle, ...)
• Regions of interest
• Convolution with custom kernel
• Sobel filter
• Morphological transformations (open, close, erode, ...)

Development

Contributions to code or documentation are welcome! Here are a few tips on how to setup a development environment for image-js.

Canvas-prebuilt

The canvas native addon library is required for all tests to pass. Canvas-prebuilt is a drop-in replacement for canvas that does not require any compiling. No need to install native dependencies.

License

MIT