(1) The complete Mac OS X core operating-system environment, which includes Mach, BSD, the I/O Kit, file systems, and networking components. Also called the kernel environment. (2) In image processing, a grid of numbers used in both convolution and morphological operations (such as dilation and erosion). It is typically represented as a square grid (or matrix) whose height and width are both odd, such as a 3 x 3 grid. Each cell in the grid contains a number. An image process that uses a kernel typically takes these numbers within the kernel and applies them to the image by undergoing a series of arithmetic operations between the kernel values and the image pixel intensity values.