[Image-SIG] Problem generating images secuences with increasing/decreasing zooms

[jhonlier suarez molina]

I am doing a tool to make animations with PIL but a have troubles when
in the secuences with consecutives zoom ins or zoom outs because the
zoomed object in the secuence get very perceptible shakes. 

I noticed that was due to the reference vertex point when the image
object is zoomed moved around the mathemathical calculated vertex point
one pixel in any direction because of the integer adjustment from exact
calculations and integer positions pixels.

I normally use the image center as vertex.

Do anyone knows how to solve this?

Any help is welcome.

Thanks in advance
Jhonlier.