> For the complete documentation index, see [llms.txt](https://docs.viesus.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.viesus.com/configuration/parameter-reference/local-parameters.md).

# Local Parameters

The Lpars section — region correction factors and per-zone adjustments for skin, sky, and vegetation.

Local parameters control corrections applied to specific image regions.

VIESUS automatically calculates the appropriate correction for each image. The strength parameters scale how much of the calculated correction is actually applied.

<table><thead><tr><th width="200">Parameter</th><th width="95">Range</th><th width="95">Default</th><th>Description</th></tr></thead><tbody><tr><td><code>highlightfac</code></td><td>0.0 – 1.0</td><td>0.5</td><td><a href="/features/features/shadow-highlight-recovery.md">Highlight region</a> correction factor</td></tr><tr><td><code>shadowfac</code></td><td>0.0 – 1.0</td><td>0.5</td><td><a href="/features/features/shadow-highlight-recovery.md">Shadow region</a> correction factor</td></tr><tr><td><code>colorfac</code></td><td>0.0 – 1.0</td><td>0.5</td><td>Region-specific color correction factor</td></tr><tr><td><code>skinToneAdjFac</code></td><td>0.0 – 1.0</td><td>0.2</td><td>Saturation reduction in <a href="/features/features/skin-tone-enhancement.md">face regions</a> (prevents "glowing" faces)</td></tr><tr><td><code>addflashfac</code></td><td>0.0 – 1.0</td><td>0.5</td><td><a href="/features/features/adaptive-face-flash.md">Adaptive shadow highlighting</a> for faces (0.3 recommended)</td></tr></tbody></table>

## Color-specific adjustments

VIESUS applies dedicated adjustments to three color regions important for image quality: **skin**, **sky**, and **vegetation**. Each lives in its own sub-section (`Lpars.skin`, `Lpars.sky`, `Lpars.veg`) and uses the same parameter set:

<table><thead><tr><th width="200">Parameter</th><th width="118.2000732421875">Range</th><th width="95">Default</th><th>Description</th></tr></thead><tbody><tr><td><code>huerotation</code></td><td>-10.0 – 10.0</td><td>0.0</td><td><a href="/features/features/local-color-correction.md">Hue rotation</a> for the specific color region</td></tr><tr><td><code>saturation</code></td><td>-1.0 – 1.0</td><td>0.0</td><td><a href="/features/features/local-color-correction.md">Saturation adjustment</a> for the region</td></tr><tr><td><code>brightness</code></td><td>-1.0 – 1.0</td><td>0.0</td><td><a href="/features/features/local-color-correction.md">Brightness adjustment</a> for the region</td></tr><tr><td><code>contrast</code></td><td>-1.0 – 1.0</td><td>0.0</td><td><a href="/features/features/local-color-correction.md">Contrast adjustment</a> for the region</td></tr><tr><td><code>strength</code></td><td>0.0 – 1.0</td><td>1.0</td><td><a href="/features/features/local-color-correction.md">Overall strength</a> of adjustments for the region</td></tr></tbody></table>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://docs.viesus.com/configuration/parameter-reference/local-parameters.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.