5.5 Image Data and DataBuffers

The DataBuffer belonging to a Raster represents an array of image data. When you create a Raster directly or through the BufferedImage constructors, you specify a width and height in pixels, along with a SampleModel for the image data. This information is used to create a DataBuffer of the appropriate data type and size.

There are three subclasses of DataBuffer, each representing a different type of data element:

• DataBufferByte (represents 8-bit values)
• DataBufferInt (represents 32-bit values)
• DataBufferShort (represents 16-bit values)
• DataBufferUShort (represents unsigned short values)

As defined earlier, elements are the discrete members of the array of the data buffer, and components or samples are the discrete values that together make up a pixel. There can be various mappings between a particular type of element in a DataBuffer and a particular type of pixel represented by a SampleModel. It is the responsibility of the various SampleModel subclasses to implement that mapping and provide a way to get specific pixels from a specific DataBuffer.

DataBuffer constructors provide ways to create buffers of a specific size and a specific number of banks.

While you can access image data in a DataBuffer directly, it's generally easier and more convenient to do so through the methods of the Raster and WritableRaster classes.