3 Color EDF|
Move your mouse over the above traditional F/8 image to view the traditional image stopped down 6 times
The above image is of inclined crayons from a traditional F/8 imaging system. The depth of field is less than one crayon width. The foreground and background are badly blurred due to misfocus. By moving your mouse over the above image you can see the same image only with the F# increased by 6 (reducing the aperture diameter by a factor of six). This increases the depth of field to include all of the crayons. The spatial resolutions and image SNR are both badly degraded in comparison to the full aperture system. The major noise component is due to quantization errors.
Move your mouse over the above F/8 cubic phase mask raw image to view the filtered F/8 cubic phase mask image
The above image is a raw image of inclined crayons from a traditional F/8 imaging system with a cubic phase optical mask. The image appears uniformly blurred throughout the entire image. If you move your mouse over the above image you can see the same image after filtering. The filtering performed is a 25 rectangularly separable 1-D convolution followed by a 2x2 median operation. The same filter was used on each color channel.
The above images illustrate the benefit of wavefront coding for increased depth of field. Compared with stopping down the lens, the optical/digital method of increasing depth of field offers a higher spatial resolution and much lower signal-to-noise ratio loss. The image artifacts noticeable near the edges of adjacent crayons are due to aliasing. No antialiasing or low pass filter was used on this system.