Moving picture encoding method, device using the same, and computer program
View Patent ↗If a reference frame displayed at the reproduction side immediately before a current image frame to be encoded is an inter encoding image frame, a quantization control device ( 999 ) appropriately corrects the level (quantization value) of an intra encoding so as to visually reduce I-frame flicker caused by a difference between the inter encoding noise characteristic of the inter encoding image frame and the noise characteristic of the current intra encoding.
1. A moving picture encoding apparatus comprising:
a memory frame for storing a past P-frame relative to an image to be intra-encoded; and
means for correcting a quantized value in intra-encoding using an inter-frame predicted image obtained by applying inter-frame prediction to said image to be intra-encoded with an image in said P-frame.
2. A moving picture encoding apparatus recited in claim 1 , wherein said P-frame is a P-frame immediately before said image to be intra-encoded.
3. A moving picture encoding apparatus recited in claim 2 , wherein said inter-frame predicted image is a reconstructed image obtained by applying inter-frame prediction, conversion, quantization, inverse-quantization, and inverse-conversion to an image to be intra-encoded with an image in said P-frame.
4. A moving picture encoding apparatus recited in claim 3 , wherein a quantized value obtained by converting a difference between said image for use in correction and an intra-frame predicted value image and applying quantization thereto is used as a quantized value in intra-encoding.
5. A moving picture encoding apparatus recited in claim 4 , wherein said quantization has a rounding-off quantizing property.
6. A moving picture encoding apparatus recited in claim 5 , wherein correction on said quantized value in intra-encoding is applied only when a difference between a transform coefficient in intra-encoding and that obtained from said image for use in correction is equal to or smaller than a quantization dead-zone width in inter- encoding.
7. A moving picture encoding apparatus recited in claim 3 , wherein a quantized value obtained by converting said image for use in correction and applying quantization thereto is used as a quantized value in intra-encoding.
8. A moving picture encoding apparatus recited in claim 7 , wherein said quantization has a rounding-off quantizing property.
9. A moving picture encoding apparatus recited in claim 8 , wherein correction on said quantized value in intra-encoding is applied only when a difference between a transform coefficient in intra-encoding and that obtained from said image for use in correction is equal to or smaller than a quantization dead-zone width in inter- encoding.
10. A moving picture encoding apparatus recited in claim 2 , comprising means for intra-encoding a reconstructed image produced by applying inter-frame prediction, conversion, quantization, inverse-quantization, and inverse-conversion to an image to be intra-encoded with an image in said P-frame.
11. A moving picture encoding apparatus recited in claim 2 , comprising means for intra-encoding an inter-frame predicted image produced by applying inter-frame prediction to an image to be intra-encoded with an image in said P-frame.
12. A moving picture encoding apparatus recited in claim 10 or claim 11 , wherein said intra-encoding is applied when a difference between said produced image and an image to be intra-encoded is equal to or smaller than a quantization dead-zone width in inter-encoding in a pixel space.
13. A moving picture encoding method comprising:
producing an inter-frame predicted image by applying inter-frame prediction to an image to be intra-encoded with an image in a past P-frame relative to the image to be intra- encoded; and
correcting a quantized value in intra-encoding using said inter-frame predicted image.
14. A moving picture encoding method recited in claim 13 , wherein said P-frame is a P-frame immediately before said image to be intra-encoded.
15. A moving picture encoding method recited in claim 14 , wherein said inter-frame predicted image is a reconstructed image obtained by applying inter-frame prediction, conversion, quantization, inverse-quantization, and inverse-conversion to an image to be intra-encoded with an image in a P-frame.
16. A moving picture encoding method recited in claim 15 , wherein a quantized value obtained by converting a difference between said image for use in correction and an intra-frame predicted value image and applying quantization thereto is used as a quantized value in intra-encoding.
17. A moving picture encoding method recited in claim 16 , wherein said quantization has a rounding-off quantizing property.
18. A moving picture encoding method recited in claim 17 , wherein correction on said quantized value in intra-encoding is applied only when a difference between a transform coefficient in intra-encoding and that obtained from said image for use in correction is equal to or smaller than a quantization dead-zone width in inter- encoding.
19. A moving picture encoding method recited in claim 15 , wherein a quantized value obtained by converting said image for use in correction and applying quantization thereto is used as a quantized value in intra-encoding.
20. A moving picture encoding method recited in claim 19 , wherein said quantization has a rounding-off quantizing property.
21. A moving picture encoding method recited in claim 20 , wherein correction on said quantized value in intra-encoding is applied only when a difference between a transform coefficient in intra-encoding and that obtained from said image for use in correction is equal to or smaller than a quantization dead-zone width in inter- encoding.
22. A moving picture encoding method recited in claim 14 , comprising intra-encoding a reconstructed image produced by applying inter-frame prediction, conversion, quantization, inverse-quantization, and inverse-conversion to an image to be intra-encoded with an image in said P-frame.
23. A moving picture encoding method recited in claim 14 , comprising intra-encoding an inter-frame predicted image produced by applying inter-frame prediction to an image to be intra-encoded with an image in said P-frame.
24. A moving picture encoding method recited in claim 22 or claim 23 , wherein said intra-encoding is applied when a difference between said produced image and an image to be intra-encoded is equal to or smaller than a quantization dead-zone width in inter-encoding in a pixel space.
25. A non-transitory computer readable medium storing a program for causing an information processing apparatus to perform moving picture encoding, wherein said program causes said information processing apparatus to act as:
means for producing an inter-frame predicted image by applying inter-frame prediction to an image to be intra-encoded with an image in a past P-frame relative to the image to be intra-encoded; and
means for correcting a quantized value in intra-encoding using said inter-frame predicted image.
26. A non-transitory computer readable medium recited in claim 25 , wherein said P-frame is a P-frame immediately before said image to be intra-encoded.
27. A non-transitory computer readable medium recited in claim 26 , wherein said inter-frame predicted image is
a reconstructed image obtained by applying inter-frame prediction, conversion, quantization, inverse-quantization, and inverse-conversion to an image to be intra-encoded with an image in a P-frame.
28. A non-transitory computer readable medium recited in claim 27 , wherein a quantized value obtained by converting said image for use in correction and applying quantization thereto is used as a quantized value in intra-encoding.
29. A non-transitory computer readable medium recited in claim 28 , wherein said quantization has a rounding-off quantizing property.
30. A non-transitory computer readable medium recited in claim 29 , wherein correction on said quantized value in intra-encoding is applied only when a difference between a transform coefficient in intra-encoding and that obtained from said image for use in correction is equal to or smaller than a quantization dead-zone width in inter- encoding.
31. A non-transitory computer readable medium recited in claim 27 , wherein a quantized value obtained by converting a difference between said image for use in correction and an intra-frame predicted value image and applying quantization thereto is used as the quantized value in intra-encoding.
32. A non-transitory computer readable medium recited in claim 31 , wherein said quantization has a rounding-off quantizing property.
33. A non-transitory computer readable medium recited in claim 32 , wherein correction on said quantized value in intra-encoding is applied only when a difference between a transform coefficient in intra-encoding and that obtained from said image for use in correction is equal to or smaller than a quantization dead-zone width in inter-encoding.
34. A non-transitory computer readable medium recited in claim 26 , wherein said program causes said information processing apparatus to act as:
means for intra-encoding a reconstructed image produced by applying inter- frame prediction, conversion, quantization, inverse-quantization, and inverse-conversion to an image to be intra-encoded with an image in said P-frame.
35. A non-transitory computer readable medium recited in claim 26 , wherein said program causes said information processing apparatus to act as:
means for intra-encoding an inter-frame predicted image produced by applying inter-frame prediction to an image to be intra-encoded with an image in said P-frame.
36. A non-transitory computer readable medium recited in claim 34 or claim 35 , wherein: said intra-encoding is applied when a difference between said produced image and an image to be intra-encoded is equal to or smaller than a quantization dead-zone width in inter-encoding in a pixel space.
37. A system for encoding/decoding a moving picture comprising:
a memory frame for storing a past P-frame relative to an image to be intra- encoded;
means for correcting a quantized value in intra-encoding using an inter-frame predicted image obtained by applying inter-frame prediction to said image to be intra-encoded with an image in said P-frame;
means for intra-encoding based on said corrected quantized value; and
decoding means for decoding said encoded data.
38. A method of encoding/decoding a moving picture comprising steps of:
producing an inter-frame predicted image by applying inter-frame prediction to an image to be intra-encoded with an image in a past P-frame relative to the image to be intra- encoded;
correcting as quantized value in intra-encoding using said inter-frame predicted image;
intra-encoding based on said corrected quantized value; and
decoding said encoded data.