TWI462031B - Image pedestrian detection device - Google Patents

Description

Image pedestrian detection device

The invention relates to an image pedestrian detection device, in particular to a method for extracting direction gradient bar graphs and features from images, and analyzing and judging the detection results to effectively improve the correct rate and reduce false alarms. The rate, and the ability to provide driver's front lane conditions, thereby improving the safety of driving.

According to the general road environment, pedestrians are one of the most important obstacles to be valued. Therefore, when pedestrians are detected while driving, they become one of the key projects for vehicle safety.

In the traditional way, it converts the problem of pedestrian detection into a model comparison problem, mainly by constructing human figures with different angles and postures, and then detecting pedestrians by means of comparison, such as: [ 1]DMGavrila, "Multi-cue Pedestrian Detection and Tracking from a Moving Vehicle," International Journal of Computer Vision , 2007., [2] DMGavrila, "Pedestrian Detection from a Moving Vehicle," in Proceedings of the European Conference on Computer Vision (ECCV), 2000. and literature [3] Cheng-Yi Liu; and Li-Chen Fu, "Computer Vision Based Object Detection and Recognition for Vehicle Driving," IEEE International Conference on Robotics and Automation , 2001, in the humanoid appearance In the representation of the feature, the human body's outline or edge image is used to represent the human form, and the humanoid template is converted into a DT (Distance Transform) image; and as in the literature [4] M. Oren, C. Papageorgiou, P.Sinha, E.Osuna, and T.Pogio. “Pedestrian detection using wavelet templates,” Proceedings of IEEE Conference on Computer Vision and Pattern Recognition , 1997, in order to more effectively overcome the variation of the object, the scale and the orientation, the Harr Vertical and Horizontal wavelets are used to calculate the humanoid feature map of the Wavelet Coefficients; As in the literature [5] Q. Zhu, S. Avidan, MCYh, and KTCheng, "Fast Human Detection Using a Cascade of Histograms of Oriented Gradients," IEEE Conf erence on Computer Vision and Pattern Recognition , 2006 and [6] N .Dalal and B. Triggs, "Histograms of Oriented Gradients for Human Detection," IEEE Conference on Computer Vision and Pattern Recognition , 2005, the Histogram of Oriented Gradients is used to represent humanoids. Features, through the SVM (Supported Vector Machine) machine learning method, the resulting classifier (Classifier) can effectively represent such features, and as a pedestrian detection in the image. In [6], the effects of different feature points applied to pedestrian detection are analyzed and discussed, including HOGs (Histogram of Oriented Gradients), Haar Wavelets, PCA-SIFT and Shape Context. The results show that HOG can overcome pedestrians. Appearance variation, and achieve good detection results HOG is calculated by dividing the image into several sub-blocks, and counting the sum of the gradients of the pixel gradients in each direction (orientation) in each block, and Form a histogram.

And it is constructed in the way of calculating the gradient. The HOG has strong ability to describe the information of the edge of the object. At the same time, due to the statistical calculation method, the HOG can tolerate the edge displacement and rotation within a considerable extent. However, due to its The nature of the calculation of the formula, HOG is quite lack of information on the material. For example, HOG is often unable to effectively separate a single complete line and fragmented lines. Therefore, if a person is in a messy environment, HOG is more prone to misjudgment.

In summary, the existing image-based driving safety devices used for pedestrian detection have a wide variety of designs and productions, and the effects obtained in the same are also different. In order to achieve effective detection of pedestrians, the detection system and its method are important technical problems that the current vehicle detection system operators need to solve.

In view of this, the inventors of this case have intensively discussed the above-mentioned problems of conventional inventions, and actively pursued solutions through years of experience in R&D and manufacturing of related industries. After long-term efforts in research and development, they finally succeeded in developing this book. Invented the "image pedestrian detection device" to improve various problems in the past.

The main purpose of the present invention is to extract the direction gradient bar graph and features from the image, and to analyze and judge the generated detection results, which can effectively improve the correct rate and reduce the false positive rate, and provide the driver in front. Lane conditions, which in turn improve the safety of driving.

In order to achieve the above object, the present invention is an image pedestrian detection apparatus comprising: an image capturing mechanism that can be disposed on a vehicle for capturing an image of a front area; and a pedestrian analysis connected to the image capturing mechanism The processing mechanism is configured to receive the image data of the previous image captured by the image capturing mechanism, and analyze whether the image data conforms to the characteristics of the pedestrian, so as to determine whether the pedestrian and the location thereof exist in the image data.

In an embodiment of the invention, the image capturing mechanism can be a camera.

In an embodiment of the present invention, the pedestrian analysis processing mechanism further includes: a composite feature capture module for extracting two pedestrian features; A support vector machine classifier can analyze and determine whether there is a pedestrian in the current feature.

In an embodiment of the present invention, the composite feature capture module further includes:

A directional gradient bar graph feature extraction system, which takes the pedestrian contour feature for subsequent use; a dense fine grain comparison feature extraction system for extracting the brightness change of the cell block in the image; and a feature combining system The feature extraction system is compared with the dense grain by the combination of the gradient gradient bar graph feature and the features are compared.

In an embodiment of the present invention, the dense fine particle comparison feature extraction system further includes: a fine grain brightness average calculation unit for calculating a brightness average value; and a dense comparison value coding unit for generating Dense fine particles compare feature values.

In an embodiment of the present invention, the dense fine particle comparison feature extraction system extracts a small area and generates a 10-dimensional vector to overcome system errors caused by image quality loss.

Please refer to "Figures 1, 2 and 3" for the respective sections. As shown in the figure: the present invention is an image pedestrian detection device that includes at least one image capture The mechanism 1 and the pedestrian analysis processing mechanism 2 are configured.

The image capturing mechanism 1 mentioned above can be disposed on the vehicle 3 for capturing images of the front area, and the image capturing mechanism 1 can be a camera.

The pedestrian analysis processing mechanism 2 is connected to the image capturing mechanism 1 for receiving the image data of the image captured by the image capturing mechanism 1 and analyzing whether the image data conforms to the characteristics of the pedestrian to determine whether the image data is in the image data. There is a pedestrian and its location, wherein the pedestrian analysis processing mechanism 2 further includes: a composite feature capture module 21 for extracting two pedestrian features; and a support vector machine classifier 22, which can be used as Analyze whether the current feature has a pedestrian.

The composite feature extraction module 21 includes: a directional gradient bar graph feature extraction system 211, which can take the pedestrian contour feature for subsequent use; a dense fine particle comparison feature extraction system 212, To extract the brightness change of the cell block in the image, and the dense particle comparison feature extraction system extracts the change of the small area and generates a 10-dimensional vector to overcome the system error caused by the image quality loss; and a feature combining system 213, in combination with the direction gradient bar graph feature extraction system 211 and the dense fine particle comparison feature capture system 212 and compare the features.

In addition, the dense fine particle comparison feature capturing system 212 further includes: a fine grain brightness average calculating unit 2121 for calculating a brightness average value; and a dense comparison value encoding unit 2122 for generating dense fine grain comparison. Eigenvalues. If so, a new image-based pedestrian detection device is constructed by the above design.

When the present invention is used, the image capturing mechanism 1 captures the image of the area in front of the vehicle 3, and inputs the image data into the pedestrian analysis processing mechanism 2, and extracts the direction gradient of the module 21 by the composite feature. The bar graph feature capture system 211 captures the direction gradient bar graph feature (HOG) in the image, and at the same time, after the dense fine particle comparison feature scooping system 212 establishes the dense fine grain comparison feature, the feature combining system 213 combines the two The heterogeneity feature is used as the feature vector required by the support vector machine classifier 22. Finally, the support vector machine classifier 22 analyzes whether the input image is a pedestrian.

In addition, in actual use, the present invention can also combine two complementary features to improve system performance. In addition to the direction gradient bar graph (HOG) feature, the finer-grained comparison feature capture system 212 is finer. The grain brightness average calculating unit 2121 and the dense comparison value encoding unit 2122 simultaneously establish a dense fine grain comparison feature, so that the feature combining system 213 connects the feature vectors generated by the two feature capturing modules into a single feature having both characteristics. The eigenvector, this single eigenvector is thus promoted to the sum of the two feature dimensions of "direction gradient bar graph" and "dense fine grain comparison". This integrated feature vector will be further used as input to the Support Vector Classifier (SVM) to determine if there is a pedestrian.

Furthermore, the fine particle (Granulc) 20 mentioned in the dense fine particle comparison feature extraction system 212 of the present invention refers to a small square area on the image; however, the present invention adopts a fixed size square shape as the fine particle 20, The average of the brightness of the image in the area to represent its connotation. In order to take out the comparative information, the average brightness of the two fine particles 20 will be used for comparison, and the value of the binary is generated to represent the comparison value of the two fine particles. The present invention is represented by bit 1, and r is used to indicate the comparison result of the two fine particles 20, and g is the average value of the brightness of the fine particles, which can be written as follows:

As shown in Fig. 3, the square block represents an image having 2 by 2 fine particles 20; the four fine particles may have a combination of up to six fine grain pairs, and the present invention defines the six combinations according to the prior definition. The order is combined with the six-digit number and expressed as 0-63. So far, the present invention completes one dimension of the intensive fine grain comparison feature vector, and the module which produces one dimension by comparison of four fine particles is called a fine grain 20 comparison module.

In addition, as shown in Fig. 4, the present invention divides the direction gradient bar graph (HOG) feature (16 by 16 pixels) into 16 equal parts (4 by 4) fine particles 20a (here each box is regarded as a thin粒), the present invention will 4 fine particles 20a, through the dense fine particle comparison feature extraction system 212 to generate one-dimensional data, and then translate the calculated range into a fine grain 20a unit, recalculate the fine particles of the four fine particles Comparing values; taking 16 equal parts of the design of the present invention as an example, a total of 3 times 3 = 9 dimensions of feature vectors can be generated; and the present invention further considers 2 by 2 fine particles 20 as large fine particles 20, re-originating the original The block performs large-scale fine-grain 20 comparison, and then generates an additional dimension of data; thus, the eigenvectors of 10 dimensions are established, and the vector is a dense fine-grain comparison feature vector, and the dense comparison coding module transmits fine particles through the call. The intensity comparison module produces dense fine grain comparison features.

In summary, the image pedestrian detection device of the present invention can effectively improve various shortcomings of the conventional use, and can extract the direction gradient bar graph and features from the image, and use the features to analyze and judge the detection result, which can effectively improve Correct rate and reduce false positive rate, and provide driver's front lane condition, thus improving driving safety Efficacy; furthermore, the invention can be made more progressive, more practical, and more in line with the needs of consumers, and has indeed met the requirements of the invention patent application, and filed a patent application according to law.

However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto; therefore, the simple equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the invention are modified. All should remain within the scope of the invention patent.

1‧‧‧Image capture agency

2‧‧‧Pedestrian analysis and processing agency

21‧‧‧Composite feature capture module

22‧‧‧Support Vector Machine Classifier

211‧‧‧ Directional gradient bar graph feature extraction system

212‧‧‧Intensive fine particle comparison feature extraction system

213‧‧‧Feature Binding System

2121‧‧‧fine grain brightness average calculation unit

2122‧‧‧Intensive comparison value coding unit

20, 20a‧‧‧ fine grain

3‧‧‧ Vehicles

Fig. 1 is a schematic view showing the state of the present invention.

Figure 2 is a block diagram of the present invention.

Figure 3 is a schematic view of the fine particles of the present invention.

Fig. 4 is a schematic view showing the comparative characteristics of dense fine particles of the present invention.

1‧‧‧Image capture agency

2‧‧‧Pedestrian analysis and processing agency

21‧‧‧Composite feature capture module

22‧‧‧Support Vector Machine Classifier

211‧‧‧ Directional gradient bar graph feature extraction system

212‧‧‧Intensive fine particle comparison feature extraction system

213‧‧‧Feature Binding System

2121‧‧‧fine grain brightness average calculation unit

2122‧‧‧Intensive comparison value coding unit

Claims (3)

An image pedestrian detection device includes: an image capture mechanism that can be disposed on a vehicle for capturing an image of a front area; and a pedestrian analysis processing mechanism coupled to the image capture mechanism for receiving The image capturing mechanism captures the image data of the front side and analyzes whether the image data conforms to the characteristics of the pedestrian, so as to determine whether there is a pedestrian and its position in the image data, wherein the pedestrian analysis processing mechanism further comprises: a composite type The feature capture module is configured to extract two kinds of pedestrian features; and a support vector machine classifier can analyze and determine whether there is a pedestrian in the current feature; and the composite feature capture module includes: a direction gradient straight bar a feature extraction system that extracts pedestrian contour features for subsequent use; a dense fine grain comparison feature extraction system for extracting brightness changes of the cell blocks in the image; and a feature combining system for combining the direction gradients The bar graph feature extraction system compares the feature extraction system with the dense fine particles and compares the features. The image-based pedestrian detection device according to the first aspect of the invention, wherein the dense fine particle comparison feature extraction system further comprises: a fine grain brightness average calculation unit for calculating a brightness average value; A dense comparison value coding unit for generating dense fine grain comparison feature values. The image type pedestrian detecting device according to claim 1, wherein the dense fine particle comparison feature extraction system extracts a small area change and generates a 10-dimensional vector for overcoming the image quality loss. system error.