TH51485B - Creating a fine grain film grain database for HD DVD. - Google Patents

Abstract

DC60 The correct generation of film grain bits is achieved by first constructing a series of coefficients. That converts the correct bits A set of coefficients that convert the correct bits through frequency filtering and subsequently correct bit inversion to obtain film grain. The correct bit formation of the film grain occurs by first constructing a series of coefficients. That converts the correct bits A set of coefficients that convert the correct bits through frequency filtering and subsequently correct bit inversion to obtain film grain.

Claims (8)

A method of generating a film grain pattern, comprising the steps of (a) generating a set of bit-corrected coefficients, (b) filtering a set of bit-corrected coefficients, and (c) performing a bit-corrected inverse transformation on the filtered coefficients to obtain the film grain pattern. 2. The method of claim 1, wherein steps (a)–(c) are repeated for all possible film grain sizes and shapes. 3. The method of claim 1, further comprising the step of (d) storing the film grain pattern in a database. 4. The method of claim 3, wherein steps (a)–(d) are repeated for all possible film grain sizes and shapes. 5. The method of claim 1, further comprising the step of scaling the film grain pattern. 6. The method of claim 1, wherein the steps of generating a set of bit-corrected coefficients comprise the step of reading the set of discrete cosine-transformed coefficients. 7. The method of claim 1, wherein the step of generating a set of bit-transform coefficients comprising the step of reading a set of integer discrete cosine transform coefficients from a database for all possible film grain sizes and shapes. 8. According to claim 1, wherein the step of generating a set of bit-transform coefficients comprising the step of generating an image of Gaussian random numbers and performing an integer discrete cosine transform on the image of Gaussian random numbers. 9. The method of claim 1, wherein the step of generating a set of bit-transform coefficients comprising the step of (i) generating an image of Gaussian random numbers, (ii) performing an integer discrete cosine transform on the image of Gaussian random numbers, and repeating steps (i) and (ii) for all possible film grain sizes and shapes. 1 0. The method of claim 1, wherein the frequency filtering step utilizes the given set. The cutoff frequencies fHL, fVL, fHH and fVH are given first, which represent the cutoff frequency (in two dimensions) of the filter, which exhibits the desired film grain characteristic 1. 1. The method of claim 1, wherein the step of performing a bitwise inverse transformation on the frequency-transformed coefficients comprises the step of performing an inverse discrete cosine transform. 2. The apparatus comprises a processor and specialized logic circuits for generating film grain patterns by (a) generating a set of bit-corrected coefficients, (b) filtering the frequency of the bit-corrected coefficients, and (c) performing bit-corrected operations on the frequency-corrected coefficients to obtain the film grain pattern. 3. The apparatus of claim 12 further comprising a first memory for storing grain film 1. 4. The apparatus of claim 12 further comprising a second memory for storing at least one set of integer discrete cosine transform coefficients. 5. The apparatus of claim 13 further comprising a second memory for storing a plurality of sets of integer discrete cosine transform coefficients 1. 6. The apparatus of claim 12 further comprising a Gaussian random generator for generating Gaussian random number images, a method for performing an integer discrete cosine transform on the Gaussian random number images to obtain a set of bit-corrected coefficients. 7. The apparatus of claim 12 further comprising a second memory for storing an image of a Gaussian random number and a method for performing an integer discrete cosine transform on the image of a Gaussian random number to obtain a set of bit-corrected coefficients. 8. A tool for generating film grain patterns, consisting of a method for generating a set of bit-corrected coefficients, a method for frequency-filtering a set of bit-corrected coefficients, and a method for performing bit-corrected coefficient conversion on the frequency-filtered coefficients to produce film grain patterns.