I'm getting the same results for Firefox and for Chrome with the above code.
An image is an inline (replaced) element and depending on browsers, doctype etc it will be placed on the baseline of the cell and not the bottom thus pushing the cell higher to allow room for descenders.
You would need to set the image to vertical-align:bottom (or set it's display to block) to kill all the whitespace.
Remember also that any whitespace between the td tags will be treated as space between words and may increase the width/height depending on browser so always close the tag at the end of the content and don;t leave gaps.
However, I didn't see any of this issues when testing with your code above but they are common issues.