A method for interpolating pixel data of an omitted line by use of pixel
data from an interlaced scan, for de-interlacing an interlaced video
image. Image edge direction is detected at the center position of every
two neighboring scan lines in an interlaced scan. All the directions
detected in a given field constitute an edge orientation map. Edge
directions are filtered to remove false and unreliable edge directions
from the edge orientation map. If an edge direction is removed, the
vertical edge direction is used to replace that direction in the edge
orientation map. For interpolating a new pixel at the center of two
neighboring scan lines, the corresponding direction for that position is
used as the interpolation direction to calculate the value of the new
pixel. If the direction is vertical, a filter is used along the vertical
direction to calculate the interpolation value. If the direction is
non-vertical, and has an integer value, then interpolation is performed
by taking the average of the two neighboring sample values along the
direction. If the direction is non-vertical and has a non-integer value,
then an interpolation value is calculated using a directional bilinear
method.