Computer Vision Foundations · free preview

The Laplacian Pyramid

Subtracting an upsampled level from its parent splits each scale band into its own image, the Laplacian pyramid, an overcomplete invertible representation that reconstructs from the tiny residual downward.

1. What each level has that its child lacks

What each level has that its child lacks

2. Upsampling, with a factor of two

Upsampling, with a factor of two

3. Building it back, downward

Building it back, downward

4. Overcomplete, and usefully so

Overcomplete, and usefully so

5. The subtraction's meaning

The Laplacian level l_k = g_k minus F_k g_{k+1} is called band-pass. What does it contain?

6. Why the factor of two

In F_k = 2 B_k U_k, why does the factor of two appear?

7. The residual count

How many low-pass residual images does a complete Laplacian pyramid keep at its tip? Write the number.

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