To be frankly, I don’t understand the PDF image you mentioned. I agreed with Suhas Dhoke’s attitude, PDF is not an image.
In addition to the codes Suhas Dhoke provided above, you can also try pdf to html converter. There are some free tools help to do the conversion automatically online or offline. People who do not familiar to programming code can try this method. 3DPageFlip just provides such kind of tools. I have found the 3DPageFlip PDF to HTML converter on the free-ebook-tool page.
Hope that helps!
I think what the OP is referring to is a vector/bitmap image embedded in a PDF file. (eg. a drawing of a cat, or a logo)
In this case, the simplest thing to do would be to convert the PDF to SVG (a good free application that will let you convert the PDF and edit it is Inkscape) and then use the <img>, <object>, <embed> or <iframe> tag to embed it in the HTML document (More info Here). This means the viewer doesn't need any additional plugins or applications to view the image, but will need a modern browser.