Because file size is a major concern when dealing with PDF documents, Acrobat provides a variety of ways to save space inside files. Following is a list of the compression methods available for different types of content. See Graphics for additional comments and options on image compression and reduction, and Fonts for information on the file space usage aspects embedding versus not embedding fonts.
Name |
Values |
Description |
PDFXv3 |
|---|---|---|---|
Graphics |
Boolean |
Specifies PDF document image compression. If this value is True, compression methods for different types of images are defined in the subsections for Color, Indexed and Mono images. Default = True |
(same) |
Text |
Boolean |
If this property is True, textual content of the PDF pages will be compressed which reduces the size of the resulting PDF document. Default = True |
(same) |
Color
Specifies compression for True color images.
Name |
Values |
Description |
PDFXv3 |
|---|---|---|---|
Enabled |
Boolean |
Default = True |
(new) |
Method |
0 (Auto) 1 (JPEG) 2 (ZIP) 3 (JPEGZIP) 4 (J2K) 5 (J2KZIP) |
Specifies compression method to be used for compressing True color images. Note that when the PDF/A specification is used for creating a PDF file, compression methods J2K and J2KZIP cannot be used. Default = 0 (Auto) |
(same) |
JPEGQuality |
1-100 |
Specifies the image quality when using JPEG compression (JPEG and JPEGZIP). Higher quality means better image definition, and a larger compressed stream, so a larger file. Default = 75 |
(same) |
Indexed
Name |
Values |
Description |
PDFXv3 |
|---|---|---|---|
Enabled |
Boolean |
If this property is True, Indexed images will be compressed by the method specified by property Method. Otherwise they will be stored into PDF without compression. Default = True |
(new) |
Method |
0 (Auto) 1 (PackBits) 2 (ZIP) 3 (LZW) |
Defines the compression method to be used to compress images with palette. The compression method LZW cannot be used with the PDF/A output specification. Default = 0 (Auto) |
(same) |
Mono
Defines the compression method to be used to compress monochrome/black and white images.
Name |
Values |
Description |
PDFXv3 |
|---|---|---|---|
Enabled |
Boolean |
Default = True |
(new) |
Method |
0 (Auto) 1 (ZIP) 2 (CCITT3) 3 (CCITT4) 4 (RLE) 5 (JBIG2) |
Defines the compression method to be used to compress monochrome/black and white images. Note that the compression method JBIG2 cannot be used with the PDF/A output specification. Default = 0 (Auto) |
(same) |
JBIG2Method |
0 (Standard) 1 (CropBorders) 2 (Symbols) |
Specifies preprocessing method of images which will be compressed using JBIG2 method. Default = 0 (Standard) |
(same) |
Examples
//;Enable compression for graphics
//PDFX,Compression.Graphics,True
//;Use automatic compression on true-color graphics
//PDFX,Compression.Color.Enabled,True
//PDFX,Compression.Color.Method,Auto
//;Disable compression of indexed graphics
//PDFX,Compression.Indexed.Enabled,False
//;Enable CCITT4 compression on mono images
//PDFX,Compression.Mono.Enabled,True
//PDFX,Compression.Mono.Method,CCITT4
//;Compress text also
//PDFX,Compression.Text,True
Compatibility
PDFXv3, v5, v9. PDFXv5+ adds the ability to independently enable the compression for the three different types of images. In PDFXv3, it was all images or none.
