The algorithm to be used when creating reduced-resolution versions of an image band. By default, the mask is computed as the `MEAN` of the input masks, reflecting the total weight of the input data over which the requested output statistic was calculated. In the case of `SAMPLE`, the sampled pixel's mask is used directly.

| Enums ||
|---|---|
| `PYRAMIDING_POLICY_UNSPECIFIED` | Not specified. |
| `MEAN` | Output pixel is the mask-weighted mean of the input pixels. Should be used for direct observation results and continuous quantities like temperature. |
| `SAMPLE` | Output pixel is identical to the upper-left input pixel. Should be used for QA/bitmask bands or other non-continuous fields like date of pixel acquisition. |
| `MIN` | Output pixel is the minimum value of the input pixels. |
| `MAX` | Output pixel is the maximum value of the input pixels. |
| `MODE` | Output pixel is the mask-weighted mode of the input pixels. Should be used for landcover bands. |
| `MEDIAN` | Output pixel is the mask-weighted median of the input pixels. In case of a tie, the mean of the middle two values is used. |