Video processing uses hardware, software, and combinations of the two for editing the images and sound recorded in video files. Extensive algorithms in the processing software and the peripheral equipment allow the user to perform editing functions using various filters. The desired effects can be produced by editing frame by frame or in larger batches.
Most modern personal computers come with software that allows the user to compile images and videos, edit images, and create videos on a limited level. Storyboards allow the addition of audio files and the adjustment of visual images, transitions, and audio files, which, together, determine the overall length of the video. Videographers, electrical engineers, and computer science professionals use programs that are capable of a wider range of functions. Signal processing usually involves applying a combination of prefilters, intrafilters, and post filters.
Video files are obtained from the recording device using a universal standard bus (USB) cable or firewire attachment. The files are then loaded into a computer software program or peripheral device. Before applying the filters used in video processing, certain programs require information for the optimization framework. This information allows the program to calculate the horizontal and vertical image gradients, determine the desired filter gradients, and establish function parameters.
Prefilters used in video processing might include contrast changes, deflicking, and noise elimination along with pixel size conversions. Contrast changes allow the processor to highlight particular areas of an image, change the lighting perspective, and darken or lighten images. Deflicking eliminates camera motion or uneven lighting effects that produce flickering on the video. Noise elimination removes artifacts, including lines or other textured effects that reduce image clarity. Using size conversions, users might change a video from 720 pixels to 1,080 pixels, crop the size of the video, or reposition the video on a background.
Processing videos using intrafilters allows users to deblock, or apply techniques that change the image quality. Deblocking removes blocking artifacts, sometimes acquired by compressed files, that reduce image clarity. Using the calculated gradient aspects of images, filters might sharpen out of focus images, apply highlighting around specified areas of an image, or add graphics and text to a video. Filters can also change entire color schemes or vary the colors within an image.
Deinterlacing is a post filter that is frequently used in video processing. When video recorders capture images, the images can overlap or interlace over each other. This creates artifacts that might include blurred images, a checkerboard effect, or lines that become visible during playback. Deinterlacing programs eliminate these problems by combining frames and allowing progressive scanning without these visual disturbances.