What are some pre-processing enhancements ?
• Adaptive de-interlacing: This method maps interlaced video from a higher sampling rate (e.g 720 x 480) into a lower rate, progressive format (352 x 240). The most basic algorithm measures the variance between two fields, and if the variance is small enough, uses an average of both fields to form a frame macroblock. Otherwise, a field area from one field (of the same parity) is selected. More clever algorithms are much more complex than this, and may involve median filtering, and multirate/ multidimensional tools. • Pre-anti-aliasing and Pre-blockiness reduction: A common method in still image coding is to pre-smooth the image before compression encoding. For example, if pre-analysis of a frame indicates that serious artifacts will arise if the picture were to be coded in the current condition, a pre-anti-aliasing filter can be applied. This can be as simple as having a smoothing severity proportional to the image activity. The pre-filter can be global (same smoothing factor for whole
Adaptive de-interlacing: This method maps interlaced video from a higher sampling rate (e.g 720 x 480) into a lower rate, progressive format (352 x 240). The most basic algorithm measures the correlation between two immediate macroblock fields, and if the correlation is high enough, uses an average of both fields to form a frame macroblock. Otherwise, a field area from one field (usually of the same parity) is selected. More clever algorithms are much more complex than this, and may involve median filtering, and multirate/multidimensional tools. Pre-anti-aliasing and Pre-blockiness reduction: A common method in still image coding is to pre-smooth the image before encoding. For example, if pre-analysis of a frame indicates that serious artifacts will arise if the picture were to be coded in the current condition (i.e. below the sweet spot), a pre-anti-aliasing filter can be applied. This can be as simple as having a smoothing severity proportional to the image activity. The pre-filter c
