Managing precision of markers on custom/Zoomify images

Now that I can see my markers I noticed they were showing up in the wrong place. I'm using an image I've processed with Zoomifier and I want to locate markers at specific pixel coordinates.

I picked three points -- upper left, upper right, and center bottom.

Then I divided everything by 100 because keeping these numbers in their natural state seemed to do weird things to the map. Then I used these in the map calculator at http://modestmaps.com/calculator.html.

I set row and column to the appropriate tile numbers and the zoom level to the highest level zoom (4). I got the following out:


var t:Transformation = new Transformation(223.81163872297782, 0, -0.5,
0, 223.81163872297785, -0.5000000000000001);

__projection = new LinearProjection(4, t);


This almost worked. No matter where I put a marker it was off by about 128 square pixels. I changed the code to


var t:Transformation = new Transformation(223.81163872297782, 0, 0,
0, 223.81163872297785,0);

__projection = new LinearProjection(4, t);


And now it's pixel perfect.

Is this something I was doing wrong? My pixel coordinates were:

(128,128), (3200,128),(1664,2432)

That's (y,x) format to mimic lat/long.