Nodejs | GM randomThreshold() Function

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

Syntax:

randomThreshold( channelType, LOWxHIGH )

Parameters: This function accept 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 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:



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// Include gm library
var 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');
});

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Output:

Example 2:

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// Include gm library
var 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');
});

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Output:

Reference:




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