Image processor is one of the most important components of a digital camera. In addition to the lens and the image sensor, Image Processor plays an essential role in the production of the digital image. Its the quality of Image Processor which is decisive for the quality of the recording. The terminologies Image Processor and Image Processing Engine are often used synonymously but they are actually not the same. Image Processor is the dedicated hardware component, whereas Image Processing Engine is the combination of software (usually the firmware) along with either a dedicated Image Processor unit or a general Processor serving the purpose of the Image Processor. One example will make the fact clear : most smartphones has no dedicated Image Processor, but it has the Image Processing Engine, which runs on the processor and graphics card (if it is present) of the smartphone. As most smartphone’s and Tablet’s hardware are manufactured by OEM, sometimes the graphics card, although physically present, is not installed at software level.
Technology behind the Image processor
The photodiodes of the image sensor recognizes only the shades of gray. To obtain color information, individual pixels with color filters for red, green and blue (RGB) filter are provided. Sometimes CMYK (Cyan, Magenta, Yellow, Black) system is used.
The image processor or the Image Processing Engine of Digital Camera calculates on the basis of data supplied from the image sensor based on the hue, saturation and luminance of the individual pixels, the correct color and brightness value for each pixel. Better the algorithm used, more natural the colors are reproduced.
Tasks of a Image Processor and Image Processing Engine of Digital Camera
Apart from the basic task described above, Image Processor and Image Processing Engine of Digital Camera serves additional tasks including evaluation of the color and brightness and analysis of the entire image to determine the correct contrast distribution of contrast and gamma value correction. Image Processor also does the work of Noise Reduction and removes other artifacts.
Proprietary names of Image Processor
Most Image Processor are closed source own researched technologies with the names like DIGIC for Canon, EXPEED for Nikon, TruePic of Olympus etc.