Node.js GM wave() Function

The wave() function is an inbuilt function in the GraphicsMagick library which is used to alter an image along with a sine wave. The function returns the true value of success. 

Syntax:

wave( amplitude, wavelength )

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

• amplitude: This parameter stores the value of the amplitude of the sine wave.
• wavelength: This parameter stores the value of the wavelength of the sine wave.

Return Value: This function returns the GraphicsMagick object with an image added. 

Original Image:

Example 1:

javascript

// Include gm library
const gm = require('gm');

// Import the image
gm('gfg.png')

// Invoke wave function with an amplitude
// values as 10 and wavelength as 3
.wave(10, 3)

// Process and Write the image
.write("wave1.png", function (err) {
    if (!err) console.log('done');
});

Output:

Example 2:

javascript

// Include gm library
const gm = require('gm');

// Import the image
gm('gfg.png')

// Set stroke color
.stroke("#fe1232")

// Set fill color
.fill("#1200ff")

// Draw Rectangle using drawRectangle function
.drawRectangle(10, 2, 130, 30, 1, 2)

// Invoke wave function with an amplitude
// as 20 and wavelength as 30
.wave(20, 30)

// Process and Write the image
.write("wave2.png", function (err) {
    if (!err) console.log('done');
});

Output:

Reference:

• http://www.graphicsmagick.org/GraphicsMagick.html#details-wave
• https://www.npmjs.com/package/gm