Data compression device of digital recording system and controlling method thereof

• US 20010021274A1
• Filed: 03/09/2001
• Published: 09/13/2001
• Est. Priority Date: 03/09/2000
• Status: Active Grant

• Current Assignee: Hanwha Techwin Co., Ltd. (Hanwha Corporation)
• Original Assignee: Samsung Techwin Corporation (Hanwha Vision Company Limited)
• Inventors: Lee, Jae-Hoon
• Granted Patent: US 6,792,156 B2
• Time in Patent Office: Days
• US Class Current: 382/240
• CPC Class Codes: G06T 7/262 using transform domain methods, e.g. Fourier domain methods
• CPC Class Codes: H04N 19/503 involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• CPC Class Codes: H04N 19/619 the transform being operated outside the prediction loop
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/99 involving fractal coding
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

Disclosed is an input image data compressor which comprises an image recording controller for generating image information on respective input objects from the input image data, generating image information on a moving object using the image information, comparing the previously input image data with the presently input image data, generating new image information on the moving object and compressing the new image information; a storage unit for storing signals or data generated during compression operation of the image recording controller in a corresponding established address; and a compressed image storage unit for storing the compressed image data compressed by the control operation of the image recording controller.

Claims

1. A data compressor for compressing input image data, comprising:

an image recording controller for generating image information on respective input objects from the input image data, generating image information on a moving object using the image information, comparing previously input image data with presently input image data, generating new image information on the moving object and compressing the new image information.

2. The data compressor of

claim 1

, wherein the data compressor further comprises:

a storage unit for storing signals or data generated during compression operation of the image recording controller in a corresponding established address; and

a compressed image storage unit for storing the compressed image data compressed by the control operation of the image recording controller.

3. The data compressor of

claim 1

, wherein the image recording controller comprises:

a wavelet converter for converting input image data into frequency image components and dividing the same according to frequency bands;

a motion band divider for dividing the frequency bands into a low frequency band that has a great amount of motion information of the moving object of the images and a high frequency band that has a small amount of motion information of the moving object of the images;

a motion detector including a fractal coefficient detector for detecting motion information on the moving object of the images using the low frequency band, and a fractal coefficient modulator for receiving a detection signal from the fractal coefficient detector and modulating a difference value between the detection signal and the fractal coefficient detected from a previous image;

a high frequency band encoder for encoding a frequency of the high frequency band divided by the motion band divider; and

a multi-step approximation unit for receiving an encoded signal of the high frequency band encoder and approximating a difference between a result value converted by the wavelet converter and a frequency band before conversion.

4. The data compressor of

claim 2

, wherein the compressed image storage unit comprises:

a data compressor for making output values modulated by the fractal coefficient modulator and those output by the multi-step approximation unit into bit stream data; and

a data transmitter for storing output values compressed by the data compressor and transmitting the same.

5. The data compressor of

claim 3

, wherein the fractal coefficient detector further comprises a motion history index used for detecting moving distance, size conversion information and generation region of the moving object of the image, recording detection results in order from the most probable one, and storing the same.

6. The data compressor of

claim 3

, wherein the fractal coefficient modulator modulates a difference between the fractal coefficient value generated from the previous image and the fractal coefficient value of the presently input image using a differential pulse code modulation (DPCM) method.

7. The data compressor of

claim 1

, wherein the image recording controller divides the input image data into predetermined categories, generates image information on the respective input objects, determines existence states of the moving object using the generated image information, and when the moving object exists, generates image information on the moving object and determines whether corresponding information exists in the previous image information, and when previous image information and image information on the moving object exists, records again only the converted image information, and when no image information on the moving object exists in the image information, records again all the image data on the moving object, and generates presently input images using the previous image data and image information and compresses the generated images.

8. The data compressor of

claim 1

, wherein when a moving object is generated, the image recording controller compares moving degrees of the object with a predetermined value, and when it is determined that the object is moved more than the predetermined value, the object is determined to be moved, and when the object is moved less than the value, the object is not determined to be moved.

9. In a data compression method using a data compressor for compressing input image data and storing the same in an information storage unit, a data compression method comprising:

(a) generating image information on a moving object from the image data and comparing the image information with previously input image data;

(b) generating image information on a new moving object and generating approximated image information; and

(c) compressing the image information on the new moving object and the generated approximated image information and storing the compressed data in the information storage unit.

10. The method of

claim 9

, wherein the comparing of (a) comprises:

removing unnecessary repetition in the input image and dividing the image into a low frequency band and a high frequency band;

comparing the image of the low frequency band that has much motion information on the moving object of the image with a key frame of a previous image from the divided bands; and

finding a number of detections and comparing the same with a reference value when a moving object is detected after the comparison.

11. The method of claim 91 wherein the generation of image information of (b) comprises:

(i) detecting, when the number of the detections is below the reference value after the comparison, motion information on the moving object from the input image, and searching whether motion information exists in the motion history index;

(ii) forming an approximated image and determining a similarity with an actual image when no motion information exists after searching the motion history index;

(iii) forming a new image when the actual image is not similar to the approximated image; and

(vi) encoding and approximating image signals of the high frequency band that has less motion information on the moving object of the image from the divided bands.

12. The method of

claim 11

, wherein the detection of the moving object of (i) comprises:

generating information for again using the key frame of the previous image, storing the same and forming the new image when no moving object is detected.

13. The method of

claim 11

, wherein the searching of the motion history index of (i) further comprises:

taking the number of the motion history index, encoding the same and forming the new image when motion information of the moving object exists.

14. The method of

claim 11

, wherein the motion history index comprises magnitude conversion information of the moving object of the image, moving distance of the moving object, and generation location region of the moving object.

15. A data compression controller, comprising:

a photographing unit for photographing an image of a subject using a pickup device unit and outputting corresponding image signals;

an image signal processor for performing image processing on the image signals output by the photographing unit and outputting corresponding image data;

a sound detector for detecting sound and outputting corresponding signals;

a data recording controller for compressing the image data output by the image signal processor when the sound is determined to be generated by the signal output by the sound detector; and

a compressed image storage unit for storing the compressed images output by the data recording controller.

16. The controller of

claim 15

, wherein the data recording controller determines, when a sound is generated by a signal output by the sound detector, whether the generated sound is greater than a predetermined size, and when the generated sound is greater than the predetermined size, the data recording controller compares the image data of the previous frame with the image data of the preset frame and determines whether the image data are changed, and when changes between the image data of the previous and present frames are generated, performs a high quality compression.

17. A data compression control method comprising:

(a) determining whether a sound is generated by a sound detecting signal;

(b) performing a compression control on input image data when it is determined that the sound is generated; and

(c) not performing the compression control on the input image data when the sound is not generated.

18. The method of

claim 17

, wherein (b) further comprises:

comparing the size of the generated sound with an established size;

comparing, when the size of the compared sound is greater than the established value, the image data of the previous frame with the image data of the present frame, and determining whether the image data are changed; and

performing a high quality compression control when the data are changed.