File Formats and Compressions
This section provides detailed information about the image formats and compressions that ImageGear supports.
- File Formats provides background information about different types of file formats, and contains additional topics that provide information on the following:
- What's the Best Format for...? lists which formats best support various types of images (for example, which formats support an alpha channel). This section provides you with a starting point for deciding which file formats to use in your application.
- Format Bit Depths is a table that lists the bit depths and the read/write capabilities of the supported formats. Using this table, you can easily find out whether an image can be converted to a particular format.
- File Formats Reference provides information about every ImageGear supported format, its ID, supported versions, encoding type, multi-page and alpha channel support, supported compressions, color spaces and bit depths for read and write, as well as information about ImageGear supported features and filter control parameters.
- Metadata Structures provides detailed information about ImageGear supported metadata.
- Compressions provides information about every ImageGear supported imaging compression.
This topic provides information about the following:
Supported Formats and Compressions
ImageGear supports the following formats and compressions in the following categories:
Raster Color and Grayscale
| Format |
Full Name |
Support |
| BMP |
Microsoft Windows Bitmap |
RW |
| CLP |
Windows Clipboard |
RW |
| CUR |
Windows cursor |
RW |
| DIB |
DIB (Microsoft Windows Device Independent Bitmap) |
RW |
| DNG |
Digital Negative file format |
R |
| GIF |
CompuServe Graphics Interchange Format (GIF) |
RW |
| JPEG |
JPEG File Interchange Format |
RW |
| TIFF |
Tagged Image File Format |
RW |
Vector
| Format |
Full Name |
Support |
| PDF |
Adobe Portable Document Format |
RW |
| SVG |
Scalable Vector Graphics |
W |
Email
| Format |
Full Name |
Support |
| EML |
Internet Message Format |
R |
| MSG |
Outlook Message Format |
R |
Office
| Format |
Full Name |
Support |
| DOCX |
Office Open XML Word Format |
R |
| DOC |
Microsoft Office Word 97-2003 Format |
R |
| PPTX |
Office Open XML PowerPoint Format |
R |
| PPT |
Microsoft Office PowerPoint 97-2003 Format |
R |
| XLSX |
Office Open XML Excel Format |
R |
| XLS |
Microsoft Office Excel 97-2003 Format |
R |
Compressions
| Format |
Full Name |
Formats Supported |
| CCITT Group 3 Compression |
CCITT Group 3 |
Adobe PDF, PS, TIFF |
| CCITT Group 3 2D Compression |
CCITT Group 3 2D |
Adobe PDF, PS, TIFF |
| CCITT Group 4 Compression |
CCITT Group 4 |
Adobe PDF, PS, TIFF |
| Deflate Compression |
Deflate Compression |
PDF, PS, TIFF, PNG |
| Huffman Compression |
Huffman Encoding |
TIFF |
| JPEG Compressions
|
JPEG Compression |
|
| LZW (Lempel-Ziv-Welch) Compression |
Lempel-Zif-Welch (LZW) Compression |
GIF, Adobe PDF, PS, TIFF |
| Packbits Compression |
Packed Bits Compression |
TIFF |
| RLE Compression |
Run Length Encoding Compression |
BMP, CLP, Adobe PDF |
Encoding vs. Compressing
These two words are often used interchangeably in discussions of graphics file formats. Encoding is actually a broad term under which compression falls. For the sake of clarity, use these terms separately with the following intended meanings:
- Encoding - The manner that data is stored when uncompressed (binary, ASCII, etc.), how it is packed (e.g., 4-bit pixels may be packed at a rate of two pixels per byte), and the unique set of symbols used to represent the range of data items.
- Compressing - A "physical" rewriting of the graphics data so that it is represented by a smaller set of data.
