I just realized that it's been more than three years since I explained the way I handle comments on this blog. It's probably time for an update as many readers are new since then.

I moderate comments on this blog. That is, when you add a comment to the post, it doesn't appear on the blog right away. I get notified by e-mail, and then I decide whether to publish your comment. If your comment is relevant to the topic of that particular post, or if it is a general suggestion or question about the overall blog (such as a suggestion for a topic), then I publish the comment. Otherwise I delete it. I try to make these decisions within the day.

I know this policy might seem draconian, but it's based on my experience back in 2006, when I first started the blog. I wasn't moderating comments then, just using some spam filtering. If you look through some of my earliest posts, you'll see that many of them have a large number of comments; some of them have more than a hundred. And almost all of these comments were irrelevant to the topic I wrote about. Instead, they were questions asking for basic help in image processing or MATLAB, help with school projects involving image processing, product support questions, etc.

After a while I realized two things: the high volume of off-topic comments was burying the on-topic conversation, and I really didn't have time (because of my other job responsibilities) to try to answer such a large volume of wide-ranging questions. So I changed my approach to handling comments.

This blog isn't a general help forum or an alternative channel for product support. There are many people willing to provide MATLAB and even image processing help via:

• MATLAB Answers

And for product support questions, please consider starting at the Support section of mathworks.com. There's really a lot of good information there.

I also get a pretty high volume of direct e-mail because my e-mail address is relatively easy to find. I do try to answer specific questions about my MATLAB Central File Exchange submissions that come in through my Author page there. Otherwise, I mostly can't answer the direct e-mail that I receive.

So please do post your comments, questions, and observations that are relevant to the day's blog post. And take advantage of the many other information channels available for your other needs.

Thanks for your understanding and for the interesting, insightful, and sometimes challenging comments that you've posted over the years.