# API reference: preprocessing

Preprocessing modules provide sklearn-compatible transformers for baseline correction, smoothing, normalization, cropping, FTIR/Raman helpers, and derivatives. For recommended pipelines, see the Preprocessing guide and workflow tutorials.

## Baseline
::: foodspec.preprocess.baseline

## Smoothing
::: foodspec.preprocess.smoothing

## Normalization & scatter correction
::: foodspec.preprocess.normalization

## Cropping
::: foodspec.preprocess.cropping

## FTIR / Raman helpers
::: foodspec.preprocess.ftir
::: foodspec.preprocess.raman

## Derivatives
::: foodspec.preprocess.derivatives
> **Status:** Archived  
> This page has been superseded by the unified API reference. See [api_reference.md](api_reference.md#preprocessing) for current preprocessing APIs.
