What is the primary function of interlaced images in video encoding?

The primary function of interlaced images in video encoding is to enhance the smoothness of motion and reduce flicker during playback. In interlaced video, the image is divided into two fields: one containing all the odd-numbered lines and the other containing all the even-numbered lines. The encoding process alternates between these two fields, first drawing the odd lines and then the even lines. This method allows for a full image display, effectively doubling the perceived frame rate without requiring more bandwidth, which can improve the overall visual experience, particularly for moving images.

By using interlaced scanning, the video can provide the illusion of less flicker and better motion interpretation without the need for a higher refresh rate. This technique was particularly important in early television broadcasts and continues to influence how video is processed, even though progressive scanning has become more common in modern displays.