No really good way to remove pixellation. It is best avoided from the start using the proper techniques to draw things.
If you want to draw a straight diagonal line:
- Click on the starting point and release the mouse button
- Move the mouse towards the end point
- Depress the Shift key, this will make a track line appear
- Move to the end point (which can be snapped on guides/grid)
- Click again to draw the line
While moving you can also depress the Ctrl key to force the lines on multiples of 15°
If you want to draw a straight diagonal line:
- Click on the starting point and release the mouse button
- Move the mouse towards the end point
- Depress the Shift key, this will make a track line appear
- Move to the end point (which can be snapped on guides/grid)
- Click again to draw the line
While moving you can also depress the Ctrl key to force the lines on multiples of 15°
Another method is to use Paths.