<!--
{
  "documentType" : "article",
  "framework" : "Accelerate",
  "identifier" : "/documentation/Accelerate/discrete-cosine-transforms",
  "metadataVersion" : "0.1.0",
  "role" : "collectionGroup",
  "title" : "Discrete Cosine transforms"
}
-->

# Discrete Cosine transforms

Transform vectors of temporal and spatial domain real values to the frequency domain, and vice versa.

## Topics

### First Steps

  <doc://com.apple.accelerate/documentation/Accelerate/signal-extraction-from-noise>

  <doc://com.apple.accelerate/documentation/Accelerate/equalizing-audio-with-discrete-cosine-transforms-dcts>

### Objects that Simplify Discrete Cosine Transforms

[`vDSP.DCT`](/documentation/Accelerate/vDSP/DCT)

A single-precision discrete cosine transform.

[`vDSP.DCTTransformType`](/documentation/Accelerate/vDSP/DCTTransformType)

An enumeration that describes the discrete cosine transform types.

### Discrete Cosine Transforms

The functions in the Discrete Cosine Transforms (DCT) family calculate a discrete cosine transform of a specified length on a vector.

[`vDSP_DCT_CreateSetup`](/documentation/Accelerate/vDSP_DCT_CreateSetup)

Builds a data structure that contains precalculated data to perform a discrete cosine transform.

[`vDSP_DCT_Type`](/documentation/Accelerate/vDSP_DCT_Type)

Constants that indicate the type for a discrete cosine transform.

[`vDSP_DCT_Execute`](/documentation/Accelerate/vDSP_DCT_Execute)

Calculates the discrete cosine transform for a vector.


---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)