Why does this cycles render have grainy edges? I am trying to simulate a camera calibration procedure using Blender and for this reason I am trying to generate images of a checkerboard pattern to use in the calibration algorithm. After rendering I noticed two problems (as you can see in the attached image):


The straight lines are "pixelated"
The angles of the squares in the pattern are not touching


Complete view:



The problem:



I am rendering with cycles at 1600x1200 resolution, the lens used is a perspective lens. The checkerboard is generated using the materials checkerboard option and roughness is set to 0.
As suggested in the comments, this is an artifact from anti-aliasing.

In the Film section of the Render tab in the Properties panel, set the Width of the Pixel Filter all the way down (0.01). That in essence turns off the anti-aliasing.




If you are using a shadeless material (Emission shader) so noise is not a problem, then there is another way to remove the anti-aliasing.
Set the samples to one.
With only one sample there are not enough samples for the anti-aliasing algorithms to work, because there is only one.