A Texel element is also known as texture pixel. It is used in computer graphics as the fundamental unit of texture space. Textures are represented by arrays of pixels. Texels can also be illustrated by image through a simple procedure like thresholding. To define their spatial relationship Voronoi tesselation can be used by the user. This is suggesting that a division is made at the half way point for the entire texture and each Texel will have a Voronoi polygon surrounding it. This polygon region contains all points that are closer to its Texel. On modern computer the Texel operation is get done on the graphic card. Clamping and wrapping are the two techniques used when a Texel is requested that is outside of the texture. Wrapping causes a texture to be repeated where as clamping causes it to be in one spot only. Clamping limits the texture size but wrapping increase the texture size.
While texturing the 3D surface (the process well known as the texture mapping) renderer maps texels for appropriate pixels in an output picture. On the modern computers, the operation is been accomplished on graphics card. Texturing procedure begins with the location in space. Location is in the world space, however generally it is in the Model space so texture moves with model. The projector function is been applied to location for changing a location from the 3element vector to 2element vector with the values that are ranging from 0 to 1. These values are then multiplied by a resolution of texture to get a location of texel. While the texel is been requested it is not on the integer position, the texture filtering is been applied. While the texel is requested, which is outside of texture, 1 of 2 methods are used: clamping and wrapping.