METHOD FOR IMAGE RECOMBINATION OF A PLURALITY OF IMAGES AND IMAGE IDENTIFICATION AND SYSTEM FOR IMAGE ACQUIRING AND IDENTIFICATION
The present invention provides a method for image recombination of a plurality of images and image identification and a system for image acquiring and identification. Features with respect to the plurality of images are recombined and enhanced so as to form a recombined image. After that, the recombined image is processed to emphasize the features of the recombined image so that the recombined image is capable of being identified easily. Furthermore, the present provides a system to perform the foregoing method, whereby reducing unidentified problems caused due to low quality image of the monitoring system.
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The present invention generally relates to an image identification technology and, more particularly, to a method for image recombination of a plurality of images and image identification and a system for image acquiring and identification, wherein features with respect to the plurality of images are recombined so as to identify the content of an image.
BACKGROUND OF THE INVENTIONThere are many people who get killed in traffic accidents. Theft and burglary using cars/motorcycles have been repeatedly reported. These may be attributed to poor image identification of license plates because of poor monitoring systems. Such monitoring systems are mostly problematic because of poor resolution (320×240 Pixels) and slant angles of the image acquiring units to cause blur or imcomplete images that cannot be recognized so that the criminals can be at large.
Conventionally, in Taiwan Patent No. 197752, a CCD camera and an image acquiring unit are used to acquire a car image in the car lane and the car image is then read by an image reading unit. Then, a logarithmic greyscale operation unit is used to calculate the logarithmic greyscale of each pixel in the car image. The image corresponding to the logarithmic greyscales is decomposed by a wavelet decomposition unit into rough images, horizontally differentiated images, vertically differentiated images and diagonally differentiated images. An image binarization unit converts the logarithmic greyscale of each pixel in the horizontally differentiated images from real numbers into binary digits 0 and 1. A rough image dividing unit determines a region with the highest sum of binary digits within the whole car image according a pre-set license plate size and thus the region is initially referred to as a license plate region. Then, a license plate slantness correction unit corrects the slantness of the image corresponding to the license plate region. Finally, a fine image dividing unit removes the part that does not correspond to the license plate from the rough license plate region.
Moreover, in Taiwan Patent Pub. No. I286027, an integrated plurality of lane free flow vehicle enforcement system is disclosed, wherein a portal framed equipment is established at the image enforcement point. The car lane is physically divided so that image enforcement can be realized with respect to various cars even though the system slows the cars to pass by the image enforcement point at a normal speed and to change lanes freely.
Moreover, in Taiwan Patent Appl. No. 200802137, a serial license plate identification system is disclosed, using a license plate character region detection module to receive an image and determine each approximate license plate range in the image. Sequences of serial identical pixels in each approximate license plate range are obtained. The sequences of serial identical pixels are erased, filtered, and connected to blocks so as to obtain the image with respect to the license plate character region in each approximate license plate range and output verified image with respect to the license plate character region after verification. Then, the verified image with respect to the license plate character region is transmitted to the a license plate character dividing and identification module to acquire all the independent character images and thus all the license plate character information after the independent character images are identified.
Moreover, Taiwan Patent No. 221193 discloses a license plate identification and monitoring apparatus used in a parking area. When a car passes by a predetermined image acquiring spot, the host is informed to enable the duplex image acquiring device to control the camera device to acquire the car license plate image, which is then processed by the an identification process to identify the characters on the license plate for car management, stolen car seeking and prevention in the parking area.
Taiwan Patent No. 226454 discloses a license plate identification method, wherein the logic relation and character strokes are used to determine the correct license plate location in the digital image. Then, ternarized difference and fuzzy inference are used to acquire the outlines of the characters on the license plate. Adaptive binarization method is used to divide the boundaries of each character. Finally, the identification result can be obtained by a feature fused median calculation using a neural network.
Moreover, Taiwan Patent No. 191905 discloses a automatic mobile license plate identification system, which comprises an image acquiring device and an image processing device that can be installed in a car to perform automatic identification on a static or moving car being monitored. The image acquiring device is capable of acquiring the image of the license plate and transmitting the image into the image processing device. The image processing device performs a precise acquiring process on the license plate characters based on fuzzy inference and performs a character identification process on the characters using character structure analysis. Therefore, identification errors due to license plate contamination, bending, character contamination or deflexion can be prevented.
Taiwan Patent No. 123259 discloses a license plate number identification apparatus installed at a spot where cars pass by so as to automatically identify the license plate number of a car. The license plate number identification apparatus uses an image acquiring device capable of acquiring an image containing the license plate and an image processing unit capable of checking the digital image according to features of the license plate number to find the license plate location, specify the range of characters, divide the characters to achieve feature identification of each characters.
Moreover, U.S. Pat. No. 4,817,166 discloses a method for reading a license plate by acquiring the boundary features such as length, height, and width of the characters on the license plate. With such information regarding the character features, geometric features of the characters such as the locations and shapes of convex hulls, turns and holes are analyzed. Finally, the structure of each character on the license plate is analyzed according to the results of the aforegoing analysis.
Moreover, U.S. Pat. No. 6,553,131 discloses an identification technology using a smart image acquiring device to perform license plate identification. A processor is installed inside the image acquiring device to perform license plate information identification. In this technology, image identification is implemented by determining a base line according to the brightness and location of the license plate image and a blur region. The image having a base line is then processed by projection to obtain the location of each character on the license plate. A statistic-based method is used so that each character is provided with a confidence index. Finally, character information on the license plate is determined according to the confidence index.
Moreover, U.S. Pat. No. 5,425,108 discloses a license plate image identification technology, wherein the acquired license plate image is processed by fuzzy interfere and the features of the license plate image is identified by structure analysis using a neural network features.
Moreover, U.S. Pat. No. 6,473,517 discloses a license plate identification technology, wherein the license plate image is identified by character segmentation. In this technology, the license plate image is divided into a plurality of regions to be converted into possible character regions (or suspected character regions). Then, the possible character regions are identified to obtain a confidence index for image identification based thereon.
U.S. Pat. No. 5,081,685 discloses a license plate identification technology, wherein image intensity information is used to identify the characters on the license plate. In this technology, the characters are separated from the background on the license plate so as to obtain the outlines of the characters by a tracking process.
SUMMARY OF THE INVENTIONThe present invention provides a method for image recombination of a plurality of images and image identification and a system for image acquiring and identification, wherein a plurality of images corresponding to a specific target are recombined to compensate the incomplete information of each image to form a recombined image with enhanced image identification.
The present invention provides a method for image recombination of a plurality of images and image identification and a system for image acquiring and identification, wherein a recombined image formed by recombining a plurality of images is identified with a plurality of similarity indexes according to the provided information in a database. The possible results are obtained according to the similarity indexes for the user to choose from with enhanced identification speed and precision.
The present invention provides a method for image recombination of a plurality of images and image identification and a system for image acquiring and identification, which is useful in identification on the identification mark of a carrier. With enhanced character features of the identification mark, multi-angle license plate identification technology can be used to help the user to identify cars that are suspected to cause accidents.
In one embodiment, the present invention provides a method for image recombination of a plurality of images, comprising steps of: acquiring a plurality of images; determining a region of interest in an image from the plurality of images and acquiring features in the region of interest; acquiring from other regions a feature region corresponding to the region of interest according to the acquired features; and performing an image recombination process to form a recombined image according to a plurality of feature regions and the region of interest.
In another embodiment, the present invention provides a method for image identification, comprising steps of: acquiring a plurality of images; determining a region of interest in an image from the plurality of images and acquiring features in the region of interest; acquiring from other regions a feature region corresponding to the region of interest according to the acquired features; and performing an image recombination process to form a recombined image according to a plurality of feature regions and the region of interest; and identifying the recombined image.
In another embodiment, the present invention provides a system for image acquiring and identification, comprising: an image input unit capable of providing a plurality of images; an image processing unit coupled to the image input unit, the image processing unit further comprising: a feature acquiring unit capable of acquiring features in a region of interest on an image from the plurality of images and acquiring from other regions a feature region corresponding to the region of interest according to the acquired features in other regions; a recombination unit capable of performing an image recombination process according to the plurality of feature regions and the region of interest to form a recombined image.
The objects and spirits of the embodiments of the present invention will be readily understood by the accompanying drawings and detailed descriptions, wherein:
The present invention can be exemplified but not limited by various embodiments as described hereinafter.
Please refer to
Referring to
Then, step 205 is performed to acquire from other regions a feature region corresponding to the ROI according to the features acquired in step 204. The feature region is acquired manually or automatically with the use of software. The feature region is determined according to the object to be identified. In the present embodiment, an identification mark of a car is used as an example. The feature region refers to a region corresponding to the identification mark. Step 205 comprises two steps as described herein. Firstly, the image stored in step 212 is read. Then, the features acquired in step 204 are loaded to perform a feature searching process on the loaded images. For example, a feature region 94 can be searched from the image in
Referring to
Then, step 208 performs an inversing operation on the pixels in the plurality of feature regions and the pixels in the region of interest respectively. The inversing operation is achieved so that the bright turns dark and the dark turns bright. The sensitivity of human eyes is saturated in a bright environment, which leads to failure in identifying the detailed structure in the bright region. Therefore, it is easier to identify the images after the inversing operation is performed to turn the bright into dark. Afterwards, step 209 is performed to form a recombined image by summing the pixels in the plurality of feature regions and the pixels in the region of interest. Since the feature region and the region of interest have been normalized to have the same image size, the greyscale values of the pixels can be summed. In step 210, an inversing operation is performed on the recombined image. Then, step 211 is performed to enhance the recombined image. The image is enhanced to improve the contrast and the brightness. Referring to
Please refer to
Please refer to
In the sample image, the non-standard image region 51 is provided as shown in
As shown in
Referring to
Please refer to
wherein ui is the greyscale value of each pixel in the sample image, while vi is the greyscale value of each pixel in the feature image, i.e., the third feature value. Moreover, ū is the average greyscale value of all the pixels in the sample image, while
Based on equation (1), a calculation is performed on each pixel in
Referring to
In image identification, images of impossible characters or digits can be excluded according to various combinations that form the identification marks. For example, in one embodiment, the identification mark can be formed as a combination of 4 leading digits and 2 following letters (as shown in
Please refer to
The image input unit 64 is capable of receiving and transmitting the plurality of images acquired by the image acquiring unit 63 to the image processing unit 61. The image processing unit 61 comprises a feature acquiring unit 610, a recombination unit 611, an enhancing unit 612 and an identification and comparison unit 613. The feature acquiring unit 610 is capable of acquiring features in the region of interest in a standard image and acquiring a feature region corresponding to the region of interest according to acquired features in other regions. The standard image is formed by choosing one image from the plurality of images. The recombination unit 611 performs an image recombination process according to the plurality of feature regions and the region of interest to form a recombined image. The recombined image is formed as disclosed in
The identification and comparison unit 4111 performs step 23 in
The identification and comparison unit 613 is electrically connected to the enhancing unit 612 to identify the recombined image. The identification and comparison unit 613 performs a calculation on each pixel in the feature image and each pixel in the plurality of sample images to obtain a similarity index of the feature image corresponding to the plurality of sample images respectively according to the flowchart in
Accordingly, the present invention discloses a method for image processing and identification and a system for image acquiring and identification with enhanced efficiency and precision. Therefore, the present invention is useful, novel and non-obvious.
Although this invention has been disclosed and illustrated with reference to particular embodiments, the principles involved are susceptible for use in numerous other embodiments that will be apparent to persons skilled in the art. This invention is, therefore, to be limited only as indicated by the scope of the appended claims.
Claims
1. A method for image recombination of a plurality of images, comprising steps of:
- acquiring a plurality of images;
- determining a region of interest in an image from the plurality of images and acquiring features in the region of interest;
- acquiring from other regions a feature region corresponding to the region of interest according to the acquired features; and
- performing an image recombination process to form a recombined image according to a plurality of feature regions and the region of interest.
2. The method for image recombination of a plurality of images as recited in claim 1, further comprising a step of performing an image enhancing process on the recombined image.
3. The method for image recombination of a plurality of images as recited in claim 1, wherein the image recombination process comprises steps of:
- performing an operation process on corresponding pixels in the plurality of feature regions and the region of interest; and
- forming the recombined image after the operation process.
4. The method for image recombination of a plurality of images as recited in claim 3, wherein the corresponding pixels are averaged in the operation process.
5. The method for image recombination of a plurality of images as recited in claim 4, further comprising a step of performing a histogram equalization process on the recombined image.
6. The method for image recombination of a plurality of images as recited in claim 3, wherein the operation process further comprises steps of:
- performing an inversing operation on the pixels in the plurality of feature regions and the pixels in the region of interest respectively;
- summing the pixels in the plurality of feature regions and the pixels in the region of interest to form the recombined image; and
- performing an inversing operation on the recombined image.
7. The method for image recombination of a plurality of images as recited in claim 1, wherein the region of interest is determined by choosing from the plurality of images an image as a standard image and choosing from the standard image a region as the region of interest.
8. The method for image recombination of a plurality of images as recited in claim 1, further comprising a step of normalizing the plurality of images.
9. A method for image identification, comprising steps of:
- acquiring a plurality of images;
- determining a region of interest in an image from the plurality of images and acquiring features in the region of interest;
- acquiring from other regions a feature region corresponding to the region of interest according to the acquired features; and
- performing an image recombination process to form a recombined image according to a plurality of feature regions and the region of interest; and
- identifying the recombined image.
10. The method for image identification as recited in claim 9, wherein the step of identifying the recombined image further comprises steps of:
- acquiring at least one feature image in the recombined image;
- providing a database comprising a plurality of sample images therein, each having respectively a standard image region and at least a non-standard image region, wherein the standard image region has pixels corresponding to a first feature value respectively, and the non-standard image region has pixels corresponding to a second feature value respectively;
- performing a calculation on a third feature value of each pixel in the feature image and the first feature value or the second feature value corresponding to each pixel in the plurality of sample images to obtain a similarity index of the feature image corresponding to the plurality of sample images respectively;
- collecting a plurality of similarity indexes with respect to the feature image compared with the plurality of sample images; and
- sorting the plurality of similarity indexes and outputting at least one of comparison results.
11. The method for image identification as recited in claim 10, wherein the calculation is based on normalized correlation matching.
12. The method for image identification as recited in claim 10, further comprising a step of normalizing the feature image to adjust the size and the angle of the feature image so that the size of the feature image is identical to the size of the sample image after acquiring the feature image from the image.
13. The method for image identification as recited in claim 10, wherein each sample image corresponds to an image of a digit or a character.
14. The method for image identification as recited in claim 10, wherein the first feature value and the second feature value are respectively a combination of a weight value and a greyscale value, and the third feature value is a greyscale value.
15. The method for image identification as recited in claim 9, wherein the recombined image comprises information regarding an identification mark on a carrier.
16. The method for image identification as recited in claim 9, wherein the image recombination process comprises steps of:
- performing an operation process on corresponding pixels in a plurality of feature regions and the region of interest; and
- forming the recombined image after the operation process.
17. The method for image identification as recited in claim 16, wherein the corresponding pixels are averaged in the operation process.
18. The method for image identification as recited in claim 17, further comprising a step of performing a histogram equalization process on the recombined image.
19. The method for image identification as recited in claim 16, wherein the operation process further comprises steps of:
- performing an inversing operation on the pixels in the plurality of feature regions and the pixels in the region of interest respectively;
- summing the pixels in the plurality of feature regions and the pixels in the region of interest to form the recombined image; and
- performing an inversing operation on the recombined image.
20. A system for image acquiring and identification, comprising:
- an image input unit capable of providing a plurality of images;
- an image processing unit coupled to the image input unit, the image processing unit further comprising: a feature acquiring unit capable of acquiring features in a region of interest on an image from the plurality of images and acquiring from other regions a feature region corresponding to the region of interest according to the acquired features in other regions; a recombination unit capable of performing an image recombination process according to the plurality of feature regions and the region of interest to form a recombined image.
21. The system for image acquiring and identification as recited in claim 20, wherein the image processing unit further comprises:
- a database comprising a plurality of sample images therein, each having respectively a standard image region and at least a non-standard image region, wherein the standard image region has pixels corresponding to a first feature value respectively, and the non-standard image region has pixels corresponding to a second feature value respectively; and
- an identification and comparison unit coupled to the recombination unit to identify the recombined image, the identification and comparison unit performing a calculation on each pixel in the feature image and each pixel in the plurality of sample images to obtain a similarity index of the feature image corresponding to the plurality of sample images respectively, the identification and comparison unit further collecting a plurality of similarity indexes with respect to the feature image compared with the plurality of sample images.
22. The system for image acquiring and identification as recited in claim 20, wherein the image processing unit is further connected to an output unit to sort the plurality of similarity indexes and output at least one of comparison results.
23. The system for image acquiring and identification as recited in claim 20, wherein the recombination unit is further connected to an enhancing unit to enhance the recombined image.
24. The system for image acquiring and identification as recited in claim 20, wherein the recombination unit is capable of normalizing the plurality of images for an image recombination process.
Type: Application
Filed: Jul 30, 2009
Publication Date: Nov 4, 2010
Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE (Hsinchu)
Inventors: Ya-Hui Tsai (Taoyuan County), Kuo-Tang Huang (Taoyuan County), Chun-Lung Chang (Hsinchu City), Lai-Sheng Chen (Hsinchu City)
Application Number: 12/512,628
International Classification: G06K 9/00 (20060101);