# CompressionCode Enum

> Compression values for generating graphics files from PDF pages.

- Product: Adobe PDF Library 21
- Language: Modern C++
- Version: 21.4.0
- HTML page: https://docs.datalogics.com/apdfl21/ModernCPP/21.4.0/enum/CompressionCode
- Version index: https://docs.datalogics.com/apdfl21/ModernCPP/21.4.0/llms.txt

**Namespace:** `datalogics_interface`

## 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 compression for the output image type.
- `None = 1`: No image compression. Valid for BMP, PNG, and TIFF outputs only.
- `Flate = 2`: Deflate algorithm (PNG only). Lossless, widely used in zip files and PDF.
- `LZW = 3`: Lempel-Ziv-Welch. Valid for GIF and TIFF; lossless, larger files retain quality.
- `G3 = 4`: CCITT Group 3 compression. TIFF only, requires gray color model. Lossless, efficient on B&W with whitespace.
- `G4 = 5`: CCITT Group 4 compression. TIFF only, requires gray color model. Lossless, based on G3.
- `DCT = 6`: Discrete Cosine Transform. Lossy, JPEG only. Best for continuous-tone images such as photographs.