Steve on Image Processing

November 6th, 2007

From the archives: All about pixel colors

When I started this blog in early 2006, one of my first series of articles was called "All About Pixel Colors." These articles discussed how MATLAB associates matrix values with specific screen pixel colors. The series talked about the two fundamental image display models (indexed and truecolor); the scaled indexed image variation; using indexed scaling to program brightness/contrast controls; and the grayscale and binary image conventions in the Image Processing Toolbox.

This material might be useful for people who have started reading this blog since then, so I've used our new category archive pages to gather the material together. In the sidebar on the right, under Categories, click on "Pixel colors."

Or, if you prefer, you can look at my MATLAB Digest article that was based on the blog postings.

I am slowly making more use of categories in my blog. If you have category suggestions, please let me know.

By Steve Eddins

16:21 UTC | Posted in Pixel colors | Permalink |

You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

4 Responses to “From the archives: All about pixel colors”

  1. wati replied on January 8th, 2008 at 10:52 UTC :

    how can i convert cm to pixels

  2. Steve replied on January 11th, 2008 at 14:10 UTC :

    Wati—Are you looking for an answer other than multiply by the number of pixels per cm?

  3. wati replied on February 26th, 2008 at 11:45 UTC :

    yes..

  4. Steve replied on March 2nd, 2008 at 09:41 UTC :

    Wati—If you don’t give me any details at all about what you mean, then that’s the best answer I can give you.

Leave a Reply

Wrap code fragments inside <pre> tags, like this:

<pre class="code">
a = magic(3);
sum(a)
</pre>

If you have a "<" character in your code, either follow it with a space or replace it with "&lt;" (including the semicolon).

About

Steve Eddins manages the Image & Geospatial development team at The MathWorks and coauthored Digital Image Processing Using MATLAB. He writes here about image processing concepts, algorithm implementations, and MATLAB.

Subscribe


Recent Comments

  • Sana: hi steve, could you explain to me how i would be able to use the dir function, to do a loop through a directory...
  • Nishtha: Sir, I have preprocessed the image in following steps: [1] adaptive histogram equalization [2] thresholding...
  • Kristof: I also strongly support the idea. I have just recently bumped into the problem that im2single was not...
  • Steve: David—I’ m glad you found it useful!
  • David Lalejini: I found your example very useful for finding connected nodes in a large set of input pairs. I start...
  • tommy: Dear Steve, I have a question,please if you are kind to help me regarding the accumulator array dimensions of...
  • Steve: Abc—I don’t know how to distinguish the faces. You might try posting your question in the MATLAB...
  • Manju: well if we have a few ovals within each other like in a cell how do we measure the distance from the center...
  • Steve: Manju—What do you mean? How is each region defined?
  • Manju: if we have 2-3 regions within each other how do we measure the regions of each one?

Blog Admin

These postings are the author's and don't necessarily represent the opinions of The MathWorks.