# CompressionCode Enum

> Compression values for generating graphics files from PDF pages.

- Product: Adobe PDF Library 21
- Language: .NET Framework
- Version: APDFL21.0.0PlusP1e
- HTML page: https://docs.datalogics.com/apdfl21/DotNetFramework/APDFL21.0.0PlusP1e/enum/CompressionCode
- Version index: https://docs.datalogics.com/apdfl21/DotNetFramework/APDFL21.0.0PlusP1e/llms.txt

**Namespace:** `Datalogics::PDFL`

## Description

Compression values for generating graphics files from PDF pages. A compression value must be provided for JPG or GIF images.

## Values

- `Default = 0`: Use the default for the output image type.
- `NONE = 1`: Use no image compression. Valid for BMP, PNG and TIFF outputs only.
- `FLATE = 2`: Deflate algorithm (PNG only). An open source standard widely used for creating zip files and with PDF.
- `LZW = 3`: Lempel-Ziv-Welch, valid for TIFF output. Valid for GIF and TIFF. A lossless algorithm, resulting files are larger but retain original quality.
- `G3 = 4`: CCITT Group3 compression. Valid for TIFF, requires colorModel gray. A lossless algorithm for black and white images that efficiently compresses whitespace.
- `G4 = 5`: CCITT Group4 compression. Valid for TIFF, requires colorModel gray. A lossless algorithm for black and white images based on G3.
- `DCT = 6`: Discrete Cosine Transform. Lossy algorithm, valid for JPEG. Best when used with continuous tone (such as photographs).