How to solve PNG image material extracted with white border

PSP themes made the icon, I used the pen pull the chart, and is inscribed along the picture, but the PSP has made the theme after extracting the software side of a circle of white is very beautiful, I pull the map background is not white.Also to be saved PNG-8.I do see some people there is no white edge icon theme, how to achieve that effect it?

can use MATLAB, if you would.

Although I do not know if MATLAB is valid and, But that magic wand 1L matting to pull the poor far more than a pen, unless the background color to pull of with different N large.

photoshop magic wand with matting