EDIT:
public bool getImage()
{
IWebElement table = driver.FindElement(By.Id(\"DIV_ID_1\"));
string name = String.
Using your original XPath, it works fine, executed both in Firefox and Chrome's developer tools and it returns the img. Does it actually return anything or just doesn't return what you'd expect? Does it error saying the element cannot be found?
This is another way of getting it:
//td[normalize-space(text())='TEST1']/../descendant::img/@src