CFImageHistogram - ColdFusion Histogram

ColdFusion Image Histogram

Example Output Color Histogram Image:
ColdFusion Color Histogram
Example Output Histogram Image:
ColdFusion Histogram
Example Source Image:
Source image
CFDump of color histogam and statistics:
cfdump of histogram


This ColdFusion component creates black/white and color image histograms.

the component will return a structure containing histogram array(s) and statistics and/or will write PNG images of the histogram.


ColdFusion 8 Version:
Uses standard Java API currently available to ColdFusion 8, no need for external libraries (JAI now avaiable to CF8). ColdFusion 8 Version now returns an image (in cfimage format) of a B/W or color histogram.


ColdFusion 7 Version:
Uses standard Java API currently available to ColdFusion, no need for external libraries. New: JAI (Java Advanced Imaging) will be used if available in ColdFusion Class Path. Using JAI provides a massive speed increase.



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Features:

  • Can be used to index colors of images so they can be searched
  • Creates Black/White and color histograms
  • Returns histogram statistics: min, max, mean, standard deviation
  • Creates B/W and color histogram images
  • Can create histogram from JPG file and path or from a buffered image
  • Can use JAI (if available in ColdFusion Class Path) or if JAI not available will standard Java API currently available to ColdFusion 6/7
  • Massive speed increase in version 0.3 when using JAI
  • Apache License, version 2


Known Issues:

  • Output PNG width currently set to 256 pixels
  • VERY slow if JAI not used
  • Histogram image output accuracy not well tested
  • Using JAI is highly recommended


 Feedback, bugs, feature request, better ideas are greatly appreciated.

ColdFusion 8 Histogram CFC Example Usage

  • getHistogram - retuns a structure that contains a histogram array[256] and histogram statistics
  • getColorHistogram - returns a structure that contains a color histogram array[3][256] and histogram statistics
  • getHistogramImage - Returns an image histogram in cfimage format
  • getColorHistogramImage - Returns a color image histogram in cfimage format
  • setBufferedImage - allows you to define a buffered image to retrieve histogram from

Example use to get color histogram array from an image:
<cfset ih = createObject("component","imageHistogramCF8").init() />
<cfset image = expandPath("01.jpg") />
<cfset hist = ih.getColorHistogram(image) />
<cfdump var="#hist#">


Example of displaying a color histogram image:
<cfimage action="read" source="01.jpg" name="image" />
<cfset ih = createObject("component","imageHistogramCF8").init() />
<cfset hist = ih.getColorHistogramImage(image) />
<cfimage action="writeToBrowser" source="#hist#" />

ColdFusion 7 Histogram CFC Example Usage

  • getHistogram - retuns a structure that contains a histogram array[256] and histogram statistics
  • getHistogramImage - Creates an image (PNG) histogram
  • getColorHistogram - retuns a structure that contains a color histogram array[3][256] and histogram statistics
  • getColorHistogramImage - Creates an color image (PNG) histogram
  • getHistogramValue - reutrn the value of the variables.histogram structure (will be empty unless one of the above functions is called first)
  • setBufferedImage - allows you to define a buffered image to retrieve histogram from without having to specify a file path
  • setImageBackgroundColor - sets the background color for the PNG images created red,green,blue,alpha

<cfscript>
//return histogram structure of supplied image
imageHistogram = createObject("component","imageHistogram").init();
histogram = imageHistogram.getHistogram(expandPath("test.jpg"));

//create histogram image
imageHistogram = createObject("component","imageHistogram").init();
imageHistogram.getHistogramImage(expandPath("test.jpg"),expandPath("hist.png"));

//return color histogram structure of supplied image
imageHistogram = createObject("component","imageHistogram").init();
histogram = imageHistogram.getColorHistogram(expandPath("test.jpg"));

//create color histogram image
imageHistogram = createObject("component","imageHistogram").init();
imageHistogram.getColorHistogramImage(expandPath("test.jpg"),expandPath("hist.png"));

//set white background PNG histogram image color
imageHistogram = createObject("component","imageHistogram").init();
imageHistogram.setImageBackgroundColor(255,255,255,255);

//get histogram from already buffered image, variable 'bufferedImage'
imageHistogram = createObject("component","imageHistogram").init();
imageHistogram.setBufferedImage(bufferedImage);
histogram = imageHistogram.getHistogram();
</cfscript>

 

Creative Commons License