Zeeshan your code was fine(Well almost). The code is
<IMG SRC="yourimage.gif" WIDTH="75" />
The reason you were getting a smaller picture is because you had not mentioned anything about the height of the picture, hence it was adjusted automatically to maintain its original ratio.
<img src="yourimage.gif" width="75" height="313" />
You can also use bimg tag
<img src="yourimage.gif" width="750" height="470" />
Although, I think bimg is used just to edit the width(help me out here Nasif Bhai).