ENCODING APPARATUS, ENCODING METHOD, AND STORAGE MEDIUM

• US 20170353681A1
• Filed: 05/24/2017
• Published: 12/07/2017
• Est. Priority Date: 06/01/2016
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Mochizuki, Shigeki
• Granted Patent: US 10,462,401 B2
• Time in Patent Office: Days
• CPC Class Codes: G06V 10/30 Noise filtering
• CPC Class Codes: G06V 10/42 Global feature extraction by analysis of the whole pattern, e.g. using frequency domain transformations or autocorrelation
• CPC Class Codes: H04N 23/12 with one sensor only
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 25/683 by defect estimation performed on the scene signal, e.g. real time or on the fly detection

Abstract

There is provided an encoding apparatus. An acquiring unit acquires an index value of a noise amount by analyzing at least a part of an optical black area that is included in raw data. A quantizing unit quantizes the raw data based on the index value. An encoding unit encodes the quantized raw data. If the index value is a first value, the quantizing unit quantizes the raw data with a first quantization step. If the index value is a second value corresponding to a larger noise amount than a noise amount in a case where the index value is the first value, the quantizing unit quantizes the raw data with a second quantization step that is larger than the first quantization step.

Claims

1. An encoding apparatus comprising:

an acquiring unit configured to acquire an index value of a noise amount by analyzing at least a part of an optical black area that is included in raw data;

a quantizing unit configured to quantize the raw data based on the index value; and

an encoding unit configured to encode the quantized raw data,

wherein if the index value is a first value, the quantizing unit quantizes the raw data with a first quantization step, and if the index value is a second value corresponding to a larger noise amount than a noise amount in a case where the index value is the first value, the quantizing unit quantizes the raw data with a second quantization step that is larger than the first quantization step.

2. The encoding apparatus according to claim 1, further comprising:

a transforming unit configured to subject the raw data to frequency transform,

wherein the quantizing unit quantizes data obtained by performing frequency transform using the transforming unit.

3. The encoding apparatus according to claim 2,

wherein if the index value is the first value, the quantizing unit quantizes a high-frequency component of the raw data with the first quantization step, and if the index value is the second value, the quantizing unit quantizes the high-frequency component of the raw data with the second quantization step.

4. The encoding apparatus according to claim 3,

wherein the quantizing unit quantizes low-frequency component data in the raw data with a same quantization step, regardless of the index value.

5. The encoding apparatus according to claim 1,

wherein the acquiring unit acquires, as the index value, a code amount of encoded data generated by quantizing and encoding at least a part of the optical black area in a frequency domain.

6. The encoding apparatus according to claim 1,

wherein the acquiring unit acquires, as the index value, a variance or a standard deviation of pixel values in at least a part of the optical black area.

7. The encoding apparatus according to claim 1,

wherein the acquiring unit performs the analysis if an image capturing condition for the raw data is a second image capturing condition under which a noise amount is predicted to be larger than a noise amount under a first image capturing condition.

8. The encoding apparatus according to claim 7,

wherein the quantizing unit quantizes the raw data with the first quantization step if the image capturing condition for the raw data is the first image capturing condition.

9. The encoding apparatus according to claim 1,

wherein the raw data includes a first area having at least a part of the optical black area, and a second area that does not include the optical black area.

10. The encoding apparatus according to claim 9,

wherein the quantizing unit quantizes the raw data including the first area and the second area with a quantization step that is determined in accordance with the index value.

11. The encoding apparatus according to claim 9,

wherein the quantizing unit quantizes the raw data in the second area with a quantization step that is determined in accordance with the index value.

12. The encoding apparatus according to claim 11,

wherein the acquiring unit acquires, as the index value, a code amount of encoded data generated by encoding the raw data in the first area, and

if the index value is the first value, the quantizing unit quantizes the raw data in the second area with the first quantization step, and if the index value is the second value, the quantizing unit quantizes the raw data in the second area with the second quantization step.

13. The encoding apparatus according to claim 9,

wherein the first area is an entire area of the optical black area, and

the second area is an effective image capturing area included in the raw data.

14. The encoding apparatus according to claim 1, further comprising an image capturing unit configured to obtain the RAW data by capturing a subject.

15. An encoding method comprising:

acquiring an index value of a noise amount by analyzing at least a part of an optical black area that is included in raw data;

quantizing the raw data based on the index value; and

encoding the quantized raw data,

wherein if the index value is a first value, the raw data is quantized with a first quantization step in the quantizing, and if the index value is a second value corresponding to a larger noise amount than a noise amount in a case where the index value is the first value, the raw data is quantized with a second quantization step that is larger than the first quantization step in the quantizing.

16. A non-transitory computer-readable storage medium which stores a program for causing a computer to execute an encoding method comprising:

acquiring an index value of a noise amount by analyzing at least a part of an optical black area that is included in raw data;

quantizing the raw data based on the index value; and

encoding the quantized raw data,

wherein if the index value is a first value, the raw data is quantized with a first quantization step in the quantizing, and if the index value is a second value corresponding to a larger noise amount than a noise amount in a case where the index value is the first value, the raw data is quantized with a second quantization step that is larger than the first quantization step in the quantizing.