Academic Company Events NI Developer Zone Support Solutions Products & Services Contact NI MyNI

Document Type: Tutorial
NI Supported: Yes
Publish Date: Sep 6, 2006

Subscribe

Add to Del.icio.us

DIGG this!


Feedback


Yes No

Related Categories

Products

Development Topic

Related Links - Developer Zone

Related Links - Products and Services

Performing a Histogram

6 ratings | 1.83 out of 5
Print

Table of Contents

  1. Description
  2. Common Applications
  3. What To Expect

Description

The histogram of a gray-scale image is the quantitative distribution of pixels as a function of gray-level value. Color images can be represented by three histograms, one for each of the primary (that is, HSL) components.

Common Applications


Histograms are useful for the following applications:
  • Image equalization (contrast enhancement)
  • Choosing thresholds for use in identifying particles (blobs) in an image

    What To Expect

An example histogram for a gray-scale image is shown below. This figure is from the IMAQ Vision User Manual.



This histogram suggests that there might be two types of dark particles in the image against a light background. Choosing threshold values between the peaks would allow you to separate the particles for further analysis.
Related Links:
IMAQ Vision User Manual
6 ratings | 1.83 out of 5
Print

Reader Comments | Submit a comment »

 

Legal
This tutorial (this "tutorial") was developed by National Instruments ("NI"). Although technical support of this tutorial may be made available by National Instruments, the content in this tutorial may not be completely tested and verified, and NI does not guarantee its quality in any way or that NI will continue to support this content with each new revision of related products and drivers. THIS TUTORIAL IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND AND SUBJECT TO CERTAIN RESTRICTIONS AS MORE SPECIFICALLY SET FORTH IN NI.COM'S TERMS OF USE (http://ni.com/legal/termsofuse/unitedstates/us/).