Leadtools.PdfCompressor Introduction

Summary

The Leadtools.PdfCompressor assembly supports saving files through Mixed Raster Content (MRC) technology. Most PDF files are saved as a single-page 24-bit (color) or 1-bit (black-and-white) raster image. Using the LEADTOOLS PDF Compressor with MRC engine, this compressor can be used to break down a page/image into smaller segments, saving each segment using compression appropriate for that segment. Thus, one page of a PDF file may have an image segment that is compressed using JPEG compression, some text in another segment that is compressed using JBIG2 compression, and another area that is compressed using CCITT compression. This whole process works to provide a PDF file with the highest-possible compression and best-possible quality, as compared to a standard Raster PDF file.

Key Features

• Supports many compression types, including:
  • ZIP (Flate compression)
  • LZW
  • FAX CCITT (G3 1D, G3 2D, G4)
  • JBIG2
  • Lossless JPEG
  • JPEG (YUV 4.4.4, YUV 4.2.2 and YUV 4.1.1)
  • JPEG2000
• Works in two modes at the page level:
  • MRC mode: enables the segmentation of the source image and then compresses the resulting segments
  • Normal mode: inserts the image into the PDF file without segmentation
• Supports read and write operations for version 1.5 and read operations for version 1.6 of the PDF standard
• Supports saving to the PDF/A format by setting the SavePdfA property
• Provides input profiles to specify source image quality. This makes controlling the segmentation process more accurate and simple. The following input profiles are supported:
  • Automatic: the PDF compressor automatically handles the process
  • Noisy
  • Scanned
  • Printed
  • Computer-generated
  • Photo
  • User: this profile is provided for advanced users
• Provides output profiles to specify the required output quality. This should also make the segmentation process easier and more accurate. The following output profiles are supported:
  • Automatic: the PDF compressor automatically handles the process
  • Poor
  • Average
  • Good
  • Excellent
  • User: this profile is provided for advanced users
• Provides control over the compression types that will be used with each type of segment. For example, FAX CCITT G4 compression to handle 1 bit/pixel segments.
• Supports background detection, where the PDF compressor tries to determine the background of the provided image. With background detection, the background segments are not stored, resulting in a more compact PDF file.
• Provides control over 1-bit and 2-bit segment detection. Detection can be set to favor 1 bit segments over 2 bit segments, and vice versa. Or, detection can be forced to 1 bit segments over 1 bit segments and vice versa.

Supported Environments

See Also

Reference

Assembly Overview

Getting Started

Programming with the LEADTOOLS PDF Compressor

PDF File Format

LEADTOOLS PDF with Mixed Raster Content (PDF) File Format

LEADTOOLS MRC Assemblies

Version History

Leadtools.PdfCompressor Assembly Changes