Who told you that the H1 element has little value?

Header elements are for text so you cannot use them for images and I very much doubt that an alt attribute would carry the same SEO weight as an H1.

Who told you that the H1 element has little value?

Many, for example:
http://www.webmasterworld.com/google/4156039.htm [webmasterworld.com]
and I feel so by myself.

An ex-googler, Vannsa Fox saids:

If you have an image as the page’s H1 tag, keep in mind that the H1 is one of the most important clues for a search engine to determine what the page is about, so consider using text instead of an image or at least using descriptive ALT text.

http://www.ninebyblue.com/blog/effectively-using-images-2/ [ninebyblue.com]

Tell me, for what reason would Google give extra weight to the alt text of an image if it's inside a heading tag?

That wouldn't make sense from Google's point of view for improving the quality of search results. "Headings are worth more so if I put something in a heading it will give me relevancy benefit" is imo significantly underestimating the refinement of Google's algorithms.

Maybe ranking algorithms were that simple years ago but I sincerely doubt it's still the case.

Well, I didn't get you to understand me correctly because English is not my native language. All I'd like to know is whether or not it is OK to use images as h1 instead of text. Text will be better. But is there any problem in using images?

You can leave the text inside the header tag but use CSS to display an image instead.

There are also other ways to display graphic equivalents to text (such as nicer/anti-aliased fonts). SIFR is one I know of.

By "images" here, I assume you mean graphic versions of the text. For this application, I was going to suggest sIFR (aka Scalable Inman Flash Replacement) as well.

Whatever you do would need to match your alternative text exactly; you want to be careful not to misrepresent anything.

The problem with traditional "alt" text is that it doesn't carry much weight. With sIFR, I've seen essentially what I would expect an H1 element to do... no magic bullet, but as a prominent text heading on a page with appropriately optimized paragraph text following, it served to tell the engines what our pages were about. I don't think "alt" text for an image would do this.

I know h1 tag has little value of SEO these days.

In my experience I would not necessarily believe fully what some of the so-called Google commentators say or write, there is a definite reverse psychology war going on here!

Used correctly all the tags and attributes can be very effective.

Header elements are for text so you cannot use them for images and I very much doubt that an alt attribute would carry the same SEO weight as an H1.

I'll disagree with the above, <h> elements can contain pretty much anything and images are at the top of the list.

Accessibility and <h1> Header Images
[webmasterworld.com...]

Yes, you can use images in <h> elements, people do it all the time. As mentioned above, you need to make sure your alt attribute matches the text in the image exactly. When you turn images off while browsing your site, it should read exactly as it does with images on.

"Content is "equivalent" to other content when both fulfill essentially the same function or purpose upon presentation to the user."

Remember the above quote, that is from the User Agent Guidelines.

This...

<h1><img src="/images/can-i-use-images-as-h1-tag.gif" width="300" height="30" alt="Can I Use Images as <h1> Tag?"></h1>

is equivalent to this...

<h1>Can I Use Images as <h1> Tag?</h1>

I have a test document to back up the above explanation. :)

Note: I would never suggest any of the hack image replacement techniques. They are nothing but hacks due to people not understanding the purpose of the alt attribute and how to use it properly.

Both sIFR and SWFObject are ways to replace indexable text with elegant Flash and have been recommended by Google. Both have been around for years and are widely used by major sites such as ABC, and that usage is growing. SWFObject is even available through Google Code.

Not hacks, IMO, but robust and dynamic solutions to the web's limited typographic options.

Thank you, everybody. I understand sIFR and SWFObject are the best solutions. I'm not familiar with the technologies so, I have to learn them.