ImageGear for .NET User Guide > ImageGear Imaging Formats Reference > ImageGear Supported File Formats Reference > IBM IOCA |
Full Name | IBM IOCA (Image Object Content Architecture) |
Format ID | ImGearFormats.ICA |
File Extension(s) | *.ica, *.mod |
Data Type | Raster Image |
Data Encoding | Binary |
IG Multipage Support | Yes |
IG Alpha Channel Support | No |
IG Metadata Update Support | No |
IG Platforms Support | WIN32, WIN64, Unix, Unix64, .NET, .NET64, MAC, Silverlight |
N/A
None
IOCA files are most often used for document storage. They are not so unusual from most file formats, except for their naming conventions, which tend to be IBM-specific.
The general structure of an IOCA image file includes a "beginning segment", an "end segment", a header component called "Image Data Parameters", a palette, and the actual image data. Most IOCA images (less than 24-bit) contain a palette. The elements of the bitmap image are referred to as Image Data Elements (IDEs), that are called pixels by most other formats. The "Object Content" refers to the combination of the header and the image data.
IBM uses fields in the header called "self-defining fields". They each contain a type code, the length of the parameter, and then the actual parameter data. They include information as resolution, size, encoding scheme, and bit depth.
There are many optional parameters. Subsets of IOCA parameters define different flavors of the IOCA, one being the IBM MO:DCA, also supported by ImageGear. Examples of optional parameters include a tiling parameter, if the image is tiled, and a Band Image parameter, which signifies that the image is saved in "bands" ("bit planes" in other formats).
Image Object Content Architecture Reference, 2d ed., copyright International Business Machines Corporation, August 1991.