Skip to main content

Image

nut.js enables you to search for images on your screen.

To represent image data, nut.js provides the Image datatype.

Image Properties#

An Image holds all the data required to perform on-screen search.

That is:

  • the image width
  • the image height
  • a buffer storing raw image data
  • the amount of color channels
  • an id

ColorMode#

Additionally, it also stores information about the order of color channels. By default, nut.js images are stored using the BGR color mode. This mode was chosen to align with a well known computer vision library.

However, since not every image processing library expects image data in BGR ordering, nut.js images provide methods to convert between BGR and RGB mode.

const bgrImage = new Image(...);
const rgbImage = bgrImage.toRGB();
const rgbImage = new Image(..., ColorMode.RGB);
const bgrImage = rgbImage.toBGR();

Image loading#

nut.js provides helpers for image loading.

loadImage receives a full path to an image, loads it and returns an Image in BGR color mode, representing this particular file. The image id will automatically be set to the path it was loaded from.

imageResources#

Often times, images are loaded to be uses as input to Screen#find or similar. For such use cases, nut.js provides the imageResources helper function to load images relative to a configured resource directory.

See Loading Images from Resource Directory and the cross platform trick for further information.

Image saving#

Similar to image loading, nut.js provides helpers for image saving as well.

saveImage receives an ImageWriterParameters object that consists of the following:

  • image: The Image to store
  • path: The path where to store the Image

nut.js will take care of possibly required color mode conversions, so you, as a user, do not have to care about it.