Method of converting resolution of video signals and apparatus using the same

An apparatus to convert resolution of an input video signal, the apparatus comprising:

• a first unit to calculate up-sampling and down-sampling ratios based on a resolution of the input video signal and a desired resolution of an output video signal;
• a second unit to calculate a number of filter tabs by multiplying up-sampling and down-sampling ratios by a number of side lobes;
• a third unit to calculate first filter coefficients of a same number of the filter tabs by multiplying a window function by a sinc function;
• a fourth unit to calculate final filter coefficients of a filter by subtracting a result of a multiplication of a Gaussian function by a window function from the first filter coefficients, and then normalizing the final filter coefficients;
• and
• first and second scaling filters to perform filtering in vertical and horizontal directions based on the final filter coefficients by modifying a sampling rate of the input video signal depending on the up-sampling and down-sampling ratios.

A computer readable medium having recorded thereon a computer readable program having computer-executable instructions for converting resolution of an input video signal, the computer instructions excluding carrier waves and comprising:

• calculating up-sampling and down-sampling ratios based on a resolution of the input video signal and a desired resolution of an output video signal;
• calculating a number of filter tabs by multiplying up-sampling and down-sampling ratios by a number of side lobes;
• calculating first filter coefficients of a same number of filter tabs by multiplying a window function by a sinc function;
• calculating final filter coefficients of a filter by subtracting a result of a multiplication of a Gaussian function by the window function from the first filter coefficients, and then normalizing the final filter coefficients;
• and
• performing filtering in vertical and horizontal directions based on the final filter coefficients by modifying a sampling rate of the input video signal depending on the up-sampling and down-sampling ratios.

An apparatus to convert resolution of an input video signal, the apparatus comprising:

• an input signal processing unit to divide the input video signal into vertical and horizontal direction components;
• first and second multiplexers to apply the vertical and horizontal direction components to first and second scaling filters;
• the first and second scaling filters to scale the vertical and horizontal direction components according to a predetermined scheme;
• a third multiplexer to combine an output of the first and second scaling filters to provide a scaled output to an output signal processing unit;
• and
• the output signal processing unit to convert the scaled output to a desired resolution.

An apparatus to convert resolution of an input video signal, the apparatus comprising:

• a video signal resolution processing unit to divide the input video signal into vertical and horizontal direction components;
• and
• a bi-level filtering system to perform filtering in vertical and horizontal directions based on final filter coefficients by modifying a sampling rate of the input video signal depending on up-sampling and down-sampling ratios,
• wherein the bi-level filtering system comprises:
• first and second multiplexers to apply the vertical and horizontal direction components to first and second scaling filters;
• the first and second scaling filters to scale the vertical and horizontal direction components according to a predetermined scheme;
• a third multiplexer to combine an output of the first and second scaling filters to provide a scaled output to an output signal processing unit;
• and
• the output signal processing unit to convert the scaled output to a desired resolution.