System and methods for random parameter filtering

• US 8,712,180 B2
• Filed: 01/17/2012
• Issued: 04/29/2014
• Est. Priority Date: 01/17/2011
• Status: Expired

• Current Assignee: UNM Rainforest Innovations (f/k/a STC.UNM) (The University of New Mexico)
• Original Assignee: UNM Rainforest Innovations (f/k/a STC.UNM) (The University of New Mexico)
• Inventors: Sen, Pradeep, Darabi, Aliakbar
• Primary Examiner(s): Do, Anh
• Application Number:
  US13/980,230
• Publication Number:
  US 20140029849A1
• Time in Patent Office: 833 Days
• Field of Search: 382/237, 382/260, 382/162, 382/167, 381/94.2, 381/94.3, 358/1.16, 358/1.9, 358/3.03, 704/226
• US Class Current: 382/260
• CPC Class Codes: G06T 15/503 Blending, e.g. for anti-aliasing
• CPC Class Codes: G06T 2200/12 involving antialiasing
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction

Abstract

The invention produces a higher quality image from a rendering system based on a relationship between the output of a rendering system and the parameters used to compute them. Specifically, noise is removed in rendering by estimating the functional dependency between sample features and the random inputs to the system. Mutual information is applied to a local neighborhood of samples in each part of the image. This dependency is then used to reduce the importance of certain scene features in a cross-bilateral filter, which preserves scene detail. The results produced by the invention are computed in a few minutes thereby making it reasonably robust for use in production environments.

Claims

1. A method for performing a random parameter filter, comprising the steps of:

rendering one or more image samples at a given sampling rate;

storing a vector of a plurality of scene features for each image sample;

saving one or more random parameters for each image sample used to calculate the image sample by a rendering system;

choosing the one or more image samples to process;

performing pre-processing on the one or more image samples;

calculating a dependency of a color and a feature of the one or more random parameters and one or more rendering system inputs to obtain a calculated dependency;

using the calculated dependency to determine a weight for each scene feature to obtain dependency information;

modifying the one or more image samples using the dependency information to obtain a final modified sample;

filtering the final modified sample to produce one or more pixels; and

outputting a final image.

2. The method for performing a random parameter filter according to claim 1, wherein the choosing step further comprises the step of conducting iterations of block around a pixel of the image sample from a large size to a small size.

3. The method for performing a random parameter filter according to claim 1, wherein the choosing step further comprises the step of selecting a random subset of image samples within each block.

4. The method for performing a random parameter filter according to claim 1, wherein the performing step further comprises the step of clustering image samples into one or more groups.

5. The method for performing a random parameter filter according to claim 4, wherein, wherein the clustering step includes the step of calculating the standard deviation of the mean for one or more pixels of the image sample.

6. The method for performing a random parameter filter according to claim 1, wherein the performing step further comprises the step of manipulating the vector by removing the mean and dividing by the standard deviation for each scene feature of the plurality of scene features for each image sample.

7. The method for performing a random parameter filter according to claim 1, wherein the dependency is a statistical dependency.

8. The method for performing random parameter filter according to claim 1, wherein the one or more scene features is at least one selected from the group comprising of:

world position, surface normal, color, texture value, texture coordinate, and shader value.

9. The method for performing random parameter filter according to claim 1, wherein the one or more rendering system inputs is at least one selected from the group comprising of:

screen position and random parameter.

10. The method for performing a random parameter filter according to claim 1, wherein the filtering step further comprises the steps of:

classifying the weight above a certain value to mean that the scene feature has little or no dependency on the one or more random parameters and the weight below a certain value to mean that the scene feature has a significant dependency on the one or more random parameters.