To clarify, the problem is any whitespace between two specific
inline (img has display:inline by default) elements that you want to touch.
So, this is okay:
[html]<p>
<img /><img /><img />
<br />
<img /><img /><img />
<br />
<img /><img /><img />
<br />
</p>[/html]
...because there's no whitespace
between the adjacent images.
These are not okay:
[html]<p>
<img />
<img />
<img />
<br />
<img />
<img />
<img />
<br />
<img />
<img />
<img />
<br />
</p>[/html]
[html]<p>
<img /> <img /> <img /><br />
<img /> <img /> <img /><br />
<img /> <img /> <img /><br />
</p>[/html]
...because any space, tab, or new line will be collapsed into a single space character and inserted between the output.