Node.js GM transparent() Function

The transparent() function is an inbuilt function in the GraphicsMagick library which is used to make the specified color transparent within the image. The function returns the true value of success.

Syntax:

transparent( color )

Parameters: This function accepts a single parameter as mentioned above and described below:  

• color: This parameter is used to specify the name of the color.

Return Value: This function returns the GraphicsMagick object.

Original Image:

Example 1:

Javascript

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

// Import the image
gm('1.png')

// Invoke transparent function on white color
.transparent('white')

// Process and Write the image
.write("transparent1.png", function (err) {
    if (!err) console.log('done');
});

Output:

Example 2: Overwriting the file.

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)

// Invoke drawRectangle function with x0: 10,
// y0: 100, x1:260, y1:210, wc: 40, wh: 40
.drawRectangle(10, 100, 260, 210, 40, 40)

// Invoke drawText in order to name the box as 1
.drawText(150, 170, "1")

// Invoke drawrectangle function with x0: 260,
// y0:100, x1: 350, y1: 210, wc: 80, wh: 80
.drawRectangle(260, 100, 350, 210, 80, 80)

// Invoke drawText in order to name the box as 2
.drawText(300, 170, "2")

// Call to drawText Function
.drawText(100, 280, "GeeksforGeeks!")

// Invoke transparent function on green color
.transparent('green')

// Process and write the image
.write("transparent2.png", function (err) {
    if (!err) console.log('done');
});

Output:

Reference:

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