Node.js GM randomThreshold() Function

Last Updated : 31 Mar, 2023

The randomThreshold() function is an inbuilt function in the GraphicsMagick library which is used to apply a random threshold to the image. The function returns the true value of success.

Syntax:

randomThreshold( channelType, LOWxHIGH )

Parameters: This function accepts two parameters as mentioned above and described below:

channelType: This parameter is used to specify the value of Channel Type as All, Intensity, Red, Green, Blue, Cyan, Magenta, Yellow, Black, and Opacity.
LOWxHIGH: This parameter is used to specify the value of the level. The threshold never exceeds the specified maximum (HIGH) and is never less than the specified minimum (LOW).

Return Value: This function returns the GraphicsMagick object.

Example 1:

javascript

// Include gm library
const gm = require('gm');
 
// Import the image
gm('1.png')
 
// Invoke randomThreshold function
// with Channel Type as 'All' and
// lowxhigh as '10x200'
.randomThreshold('All', '10x200')
 
// Process and Write the image
.write("randomThreshold1.png", function (err) {
    if (!err) console.log('done');
});

Output:

Example 2:

javascript

// Include gm library
const gm = require('gm');
 
// Import the image
gm(600, 300, 'white')
 
// Set the color for the stroke
.stroke("green", 3)
 
// Set the font
.font("Helvetica.ttf", 60)
 
// Call to drawText Function
.drawText(100, 280, "GeeksforGeeks!")
 
// Invoke random Threshold function
// with Channel Type as 'Green' and
// lowxhigh as 100x600
.randomThreshold('Green', '100x600')
 
// Process and write the image
.write("randomThreshold2.png", function (err) {
    if (!err) console.log('done');
});