Method and apparatus for coding images with different image qualities for each region thereof, and method and apparatus capable of decoding the images by adjusting the image quality

• US 20050286741A1
• Filed: 06/29/2005
• Published: 12/29/2005
• Est. Priority Date: 06/29/2004
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Okada, Shigeyuki, Watanabe, Tsuyoshi
• Granted Patent: US 7,720,295 B2
• Time in Patent Office: Days
• US Class Current: 382/107
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/127 Prioritisation of hardware or computational resources
• CPC Class Codes: H04N 19/146 Data rate or code amount at the encoder output
• CPC Class Codes: H04N 19/162 User input
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets

Abstract

A region of interest is set within an image, the region of interest is tracked along motion of an object marked out within the image, and coding is performed in a manner that image quality differs between the region of interest and a region other than the region of interest. A wavelet transform unit applies a low-pass filter and a high-pass filter in the respective x and y directions of an original image, and divides the image into four frequency sub-bands so as to carry out a wavelet transform. A quantization unit quantizes, with a predetermined quantizing width, the wavelet transform coefficients outputted from the wavelet transform unit. A motion detector detects the motion of an object. A ROI setting unit moves a ROI region according to this motion of an object. In the case of moving images where a viewpoint changes, the background may be separated from the object and then the ROI region may be moved according to the motion of the object and the motion of the background.

Claims

1. An image coding method characterized in that a region of interest is set within an image, the region of interest is tracked along motion of an object marked out within the image, and coding is performed in a manner that image quality differs between the region of interest and a region other than the region of interest.

2. An image coding apparatus, including:

a region-of-interest setting unit which sets a region of interest within an image;

a motion detector which detects motion of an object marked out within the image; and

a coding unit which codes images with image quality that differs between the region of interest and a region other than the region of interest,

wherein said region-of-interest setting unit has the region of interest follow the motion of an object.

3. An image coding apparatus according to claim 2, further including an image quality setting unit which sets an image quality for the region other than the region of interest, based on an allotted code amount.

4. An image coding apparatus according to claim 2, further including an object extracting unit which separates background in moving images where a viewpoint changes, wherein said region-of-interest setting unit has the region of interest follow the motion of an object, in accordance with motion of the background.

5. An image coding apparatus according to claim 3, further including an object extracting unit which separates background in moving images where a viewpoint changes, wherein said region-of-interest setting unit has the region of interest follow the motion of an object, in accordance with motion of the background.

6. An image pickup apparatus having an image pickup unit which acquires an image, wherein a region of interest is set within the image, the region of interest is tracked along motion of an object marked out within the image, and coding is performed in a manner that image quality differs between the region of interest and a region other than the region of interest.

8. An image pickup apparatus according to claim 6, further including an image quality setting unit which sets an image quality for the region other than the region of interest, based on an allotted code amount.

10. An image pickup apparatus according to claim 6, further including an object extracting unit which separates background in moving images where a viewpoint changes, wherein said region-of-interest setting unit has the region of interest follow the motion of an object, in accordance with motion of the background.

7. An image pickup apparatus, including:

an image pickup unit which acquires an image;

a region-of-interest setting unit which sets a region of interest within an image;

a motion detector which detects motion of an object marked out within the image; and

a coding unit which codes images with image quality that differs between the region of interest and a region other than the region of interest,

wherein said region-of-interest setting unit has the region of interest follow the motion of an object.

9. An image pickup apparatus according to claim 7, further including an image quality setting unit which sets an image quality for the region other than the region of interest, based on an allotted code amount.

11. An image pickup apparatus according to claim 7, further including an object extracting unit which separates background in moving images where a viewpoint changes, wherein said region-of-interest setting unit has the region of interest follow the motion of an object, in accordance with motion of the background.

12. An image decoding method characterized in that a region of interest is set within an image, the region of interest is tracked along motion of an object marked out within the image, and moving images are decoded in a manner that an image quality for the region of interest differs from that for a region other than the region of interest.

13. An image decoding apparatus, including:

a region-of-interest setting unit which sets a region of interest within an image;

a motion detector which detects motion of an object marked out within the image; and

a decoding unit which decodes moving images in a manner that an image quality for the region of interest differs from that for a region other than the region of interest,

wherein said region-of-interest setting unit has the region of interest follow the motion of an object.

14. An image decoding apparatus according to claim 13, further including an image quality setting unit which sets an image quality for at least one of the region of interest and the region other than the region of interest by referring to a state of the apparatus.

15. An image decoding apparatus according to claim 14, wherein said image setting unit sets the image quality by referring to reproduction speed.

16. An image pickup apparatus having an image pickup unit which acquires an image, wherein a region of interest is set within an image, the region of interest is tracked along motion of an object marked out within the image, and moving images are displayed in a manner that an image quality for the region of interest differs from that for a region other than the region of interest.

18. An image pickup apparatus according to claim 16, further including an image quality setting unit which sets an image quality for at least one of the region of interest and the region other than the region of interest by referring to a state of the apparatus.

20. An image pickup apparatus according to claim 18, wherein said image setting unit sets the image quality by referring to reproduction amount.

17. An image pickup apparatus, including:

an image pickup unit which acquires an image;

a region-of-interest setting unit which sets a region of interest within the image;

a motion detector which detects motion of an object marked out within the image;

a coding unit which codes moving images in a manner that an image quality for region of interest differs from that for a region other than the region of interest; and

a decoding unit which decodes image data coded by said coding unit,

wherein said region of interest setting unit has the region of interest follow the motion of an object.

19. An image pickup apparatus according to claim 17, further including an image quality setting unit which sets an image quality for at least one of the region of interest and the region other than the region of interest by referring to a state of the apparatus.