Pulse or digital communications – Bandwidth reduction or expansion
Reexamination Certificate
1999-08-03
2003-07-01
Kelley, Chris (Department: 2613)
Pulse or digital communications
Bandwidth reduction or expansion
Reexamination Certificate
active
06587505
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an image processing apparatus for high-efficiently encoding/decoding an image signal and a method for such an apparatus.
2. Related Background Art
In recent years, owing to the advancement of digital signal processing techniques, a large amount of digital information such as motion image, still image, audio sound, or the like can be high-efficiently encoded, recorded to a small magnetic medium, and transmitted to a communication medium. Multimedia equipment which can mixedly handle a motion image and a still image and, further, a plurality of video images of different resolutions by using those techniques is being examined.
FIG. 1
shows a conventional constructional example of a high efficient coding apparatus which can mixedly record/reproduce a motion image of a low resolution and a still image of a high resolution.
In
FIG. 1
, either a low resolution video signal or a high resolution video signal is selectively inputted to a video signal input terminal
101
and supplied to a low resolution video coding circuit
102
and a high resolution video coding circuit
103
. Each of the low resolution video coding circuit
102
and high resolution video coding circuit
103
performs processes such as orthogonal transformation, quantization, and variable length coding to the signal which is supplied, thereby high-efficiently encoding the signal and transmitting the encoded signal to a switching circuit
104
.
The switching circuit
104
selects the signal supplied from the low resolution video coding circuit
102
when the input signal to the input terminal
101
is the low resolution video signal. The switching circuit
104
selects the signal supplied from the high resolution video coding circuit
103
when the input signal to the input terminal
101
is the high resolution video signal. The selected signal is recorded onto a recording medium
105
.
An audio signal which is inputted to an audio signal input terminal
106
is encoded by an audio coding circuit
107
and recorded onto the recording medium
105
. An additional information signal which is inputted to an additional information input terminal
108
is encoded by an additional information coding circuit
109
and recorded into a video recording area on the recording medium
105
.
That is, in the apparatus, only either the low resolution video coding circuit
102
or the high resolution video coding circuit
103
is validated by the switching circuit
10
-
4
and only either one of their outputs is recorded onto the recording medium
105
, hereby realizing the high efficient coding for the video signals of a plurality of resolutions.
FIG. 2
shows a constructional example of a conventional decoding apparatus.
In
FIG. 2
, a video code recorded on a recording medium
201
is supplied to a low resolution video decoding circuit
202
and a high resolution video decoding circuit
203
. Each of the low resolution video decoding circuit
202
and high resolution video decoding circuit
203
performs processes such as variable length decoding, inverse quantization, and inverse orthogonal transformation to the supplied video code, thereby decoding it to the original video signal and transmitting the decoded signal to a switching circuit
204
.
The switching circuit
204
selects the signal supplied from the low resolution video decoding circuit
202
when the video code supplied from the recording medium
201
is the low resolution video image. The switching circuit
204
selects the signal supplied from the high resolution video decoding circuit
203
when the video code supplied from the recording medium
201
is the high resolution video image. The selected signal is outputted to a video signal output terminal
205
.
An audio code recorded on the recording medium
201
is decoded to an audio signal by an audio decoding circuit
206
and outputted from an audio signal output terminal
207
. Similarly, an additional information code recorded on the recording medium
201
is decoded to the additional information signal by an additional information decoding circuit
208
and outputted from an additional information signal output terminal
209
.
In the above conventional apparatus, when the motion image of the low resolution and the still image of the high resolution are mixedly processed, since the different coding/decoding circuits are used for the motion image of the low resolution and the still image of the high resolution, a very large circuit scale is required. Generally, in many cases, the MPEG1 system is used for the coding/decoding circuit of the motion image of the low resolution and the JPEG system is used for the coding/decoding circuit of the still image of the high resolution. Further, the recording medium on which the still image of the high resolution has been recorded by the above apparatus cannot be used at all in a conventional apparatus corresponding only to the motion image of the low resolution.
As a simpler conventional construction, an apparatus such that a still image of a high resolution is divided into a plurality of still images of a low resolution and a coding/decoding circuit of a low resolution is used in common has been proposed. However, since distortion, aliasing, and oscillation occur in the image due to the image division, reproducibility in case of reproducing an image by the conventional apparatus is low. Particularly, when still images are continuously reproduced in a manner similar to a motion image, such distortion, aliasing noise, and oscillation occur like noises.
SUMMARY OF THE INVENTION
In consideration of the circumstances as mentioned above, it is an object of the invention to provide an image processing apparatus which can mixedly perform high efficient coding/decoding processes to a low resolution image and a high resolution image by a small circuit scale while a high picture quality is maintained without losing compatibility with an apparatus corresponding only to the low resolution image and to provide a method for such an apparatus.
For this purpose, according to one aspect of the present invention, there is provided an image processing apparatus/method comprising the steps of: selectively inputting a first image signal and a second image signal whose resolution is higher than that of the first image signal; separating a low frequency component and a high frequency component from the second image signal; encoding the first image signal or the image signal of the separated low frequency component; and encoding the image signal of the separated high frequency component.
According to another aspect of the present invention, there is provided an image processing apparatus/method comprising the steps of: separating a low frequency component and a high frequency component from a first image signal; converting a resolution of the image signal of the low frequency component and encoding the converted image signal; encoding the image signal of the high frequency component; and decoding the image signal of the low frequency component and the image signal of the high frequency component which were independently encoded, wherein the encoded image signal of the low frequency component is decoded, the encoded image signal of the high frequency component is decoded, and the decoded image signal of the low frequency component and the decoded image signal of the high frequency component are synthesized.
According to still another aspect of the present invention, there is provided an image processing apparatus/method for storing an encoded motion image signal constructed by (n×m) pixels into an image storage area on a recording medium, comprising the steps of: receiving an image signal constructed by (N×M) pixels (N>n, M>m); extracting the image signal of (n×m) pixels corresponding to a low frequency component of the received image signal; encoding the extracted image signal of (n×m) pixels; storing the encoded image signal into the image storage area on the recording medium; extracting a
Hori Taizo
Nozawa Shingo
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Kelley Chris
Senfi Behrooz
LandOfFree
Image processing apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image processing apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image processing apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3049371