# US 12,112,496 B2 · Method of piecewise linear scaling of geometry atlas and apparatus using the same

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- Number: US 12,112,496 B2
- Document ID: US12112496B2
- Status: Granted
- Kind: B2
- Application number: 17/569,944
- Filed: 2022-01-06
- Published: 2022-07-07
- Granted: 2024-10-08
- Earliest claimed: 2021-01-07
- Assignees: Electronics and Telecommunications Research Institute; Industry-University Cooperation Foundation Korea Aerospace University
- Applicants: Electronics and Telecommunications Research Institute; Industry-University Cooperation Foundation Korea Aerospace University
- Inventors: Kwan-Jung Oh; Gwang-Soon Lee; Do-Hyeon Park; Jae-Gon Kim; Sung-Gyun Lim
- Web page: https://patentgrep.com/patent/US12112496B2

## CPC

- G06T 7/55: from multiple images
- G06T 9/001: {Model-based coding, e.g. wire frame}
- G06T 7/536: from perspective effects, e.g. by using vanishing points
- G06T 9/005: {Statistical coding, e.g. Huffman, run length coding}
- G06T 9/008: {Vector quantisation}
- H04N 19/597: specially adapted for multi-view video sequence encoding
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Disclosed herein is a method for piecewise linear scaling of a geometry atlas, the method including generating min-max normalized depth values and generating geometry atlases by scaling the depth values so as to correspond to the gradients of multiple linear intervals.

## Claims

### Claim 1

A method for piecewise linear scaling of a geometry atlas, performed in an immersive video encoder, comprising:
generating min-max normalized depth values; and
generating geometry atlases by scaling the depth values so as to correspond to gradients of multiple linear intervals.

### Claim 2 (depends on 1)

The method of claim 1, wherein:
the linear intervals are generated by dividing an entire range corresponding to the min-max normalized depth values into equal intervals.

### Claim 3 (depends on 1)

The method of claim 1, further comprising:
generating an encoded immersive video signal using the geometry atlases.

### Claim 4 (depends on 1)

The method of claim 1, wherein:
the gradients are set based on sample occurrence frequencies in the linear intervals.

### Claim 5 (depends on 4)

The method of claim 4, wherein:
each of the gradients is set higher as the sample occurrence frequency is higher.

### Claim 6 (depends on 4)

The method of claim 4, wherein:
the sample occurrence frequencies are clipped into a predetermined range.

### Claim 7 (depends on 4)

The method of claim 4, wherein:
the linear intervals are signaled using syntax fields including a first field indicating a number of linear intervals and a second field indicating a scaled value corresponding to each of the linear intervals.

### Claim 8 (depends on 7)

The method of claim 7, wherein:
the syntax fields further include a third field indicating a start depth value to which the piecewise linear scaling is applied.

### Claim 9

A method for inverse scaling of a geometry atlas, performed in an immersive video decoder, comprising:
restoring geometry atlases; and
generating min-max normalized depth values by performing inverse scaling on the geometry atlases so as to correspond to gradients of multiple linear intervals.

### Claim 10 (depends on 9)

The method of claim 9, wherein:
the linear intervals are generated by dividing an entire range corresponding to the min-max normalized depth values into equal intervals.

### Claim 11 (depends on 9)

The method of claim 9, further comprising:
generating a virtual view image using the min-max normalized depth values.

### Claim 12 (depends on 9)

The method of claim 9, wherein:
the gradients are set based on sample occurrence frequencies in the linear intervals.

### Claim 13 (depends on 12)

The method of claim 12, wherein:
each of the gradients is set such that more bits are assigned as the sample occurrence frequency is higher.

### Claim 14 (depends on 12)

The method of claim 12, wherein:
the linear intervals are signaled using syntax fields including a first field indicating a number of linear intervals and a second field indicating a scaled value corresponding to each of the linear intervals.

### Claim 15 (depends on 14)

The method of claim 14, wherein:
the syntax fields further include a third field indicating a start depth value to which piecewise linear scaling is applied.

### Claim 16

An apparatus for piecewise linear scaling, comprising:
memory in which at least one program is recorded; and
a processor for executing the program,
wherein the program includes instructions for performing
generating min-max normalized depth values; and
generating geometry atlases by scaling the depth values so as to correspond to gradients of multiple linear intervals.

### Claim 17 (depends on 16)

The apparatus of claim 16, wherein:
the linear intervals are generated by dividing an entire range corresponding to the min-max normalized depth values into equal intervals.

### Claim 18 (depends on 16)

The apparatus of claim 16, wherein:
the gradients are set based on sample occurrence frequencies in the linear intervals.

### Claim 19 (depends on 18)

The apparatus of claim 18, wherein:
each of the gradients is set higher as the sample occurrence frequency is higher.

### Claim 20 (depends on 18)

The apparatus of claim 18, wherein:
the linear intervals are signaled using syntax fields including a first field indicating a number of linear intervals and a second field indicating a scaled value corresponding to each of the linear intervals.