Shear an image for a game.

hey guys my team and i have a big Problem . We design a game called “sepgarbage”. Now we have the problem to draw the street. We have an image which only go straight. Now we want to build curves with shear function in graphics2d.

We cant use other libraries. Also we dont understand this guide
http://www.extentofthejam.com/pseudo/
How we shear the image to get curves


http://s7.directupload.net/images/130620/temp/tvanpoxu.png

Sry fir my English I am from Germany