Texture Stretching

Hi, I am trying to project a scene on a curved screen… Currently I capture scene from the framebuffer and save it in a texture in the first pass of the render loop and in the second pass of the render loop apply the texture to a curved surface which is made of triangle strips. The problem is, the texture image is getting stretched particularly on the corners. The dimensions of the texture are same as that of framebuffer, however the aspect ratio are different. i.e the projection screen is a wide screen 16:9 while the scene image is captured at 4:3. Can someone please help me figure out the solution to this problem?

Power of 2 or non power of 2 texture?

If you use gluBuildMipmaps, it will stretch or shrink to make a power of 2.