[0037] In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention:
[0038] like figure 1 Shown: the present invention discloses a computer-aided screening method for a motor vehicle VIN code rubbing film, comprising the following steps:
[0039] Step S1, extract the file, scan the original VIN code rubbing film and the rubbing film to be screened and save it as an image file of the same format, and the system extracts and opens the original VIN code rubbing film image and the rubbing film image to be screened;
[0040] Step S2, select two sets of feature point pairs, respectively extract the original VIN code rubbing film image and the VIN code feature points located at the same position in the VIN code character area in the original VIN code rubbing film image and the rubbing film image to be discriminated, form a set of feature point pairs, and use the same method to extract another set of feature point pairs;
[0041] Step S3, image normalization, according to the positions of the two sets of feature point pairs, normalized image display is performed on the original VIN code rubbing film image and the VIN code character area of the rubbing film image to be discriminated, and the original VIN code rubbing is obtained. The VIN code character image of the film and the VIN code character image of the rubbing film to be screened, such as figure 2 shown, including:
[0042] Step S301, calculate the image scale according to the position of two groups of feature points, and scale the rubbing film image to be screened according to the image scale, so that the original VIN code rubbing film image and the VIN code character area of the rubbing film image to be screened same size;
[0043] Step S302, based on the original VIN code rubbing film image, calculate the angle difference between the scaled rubbing film image to be discriminated and the original VIN code rubbing film image, and conduct the screening rubbing film image according to the angle difference. Rotation, including:
[0044] When the image of the rubbing film to be discriminated is rotated counterclockwise, coordinate transformation is performed according to the following formula:
[0045] x'=x·cos(a)+y·sin(a)
[0046] y′=ycos(a)+(w-x) sin(a)
[0047] Among them, x is the abscissa of the rubbing film image to be screened before rotation, y is the ordinate of the rubbing film image to be screened before rotation, a is the angle between the rubbing film image to be screened before rotation and the original VIN code rubbing film image Poor; w is the width of the rubbing film image to be discriminated, x' is the abscissa of the rubbing film image to be discriminated after rotation, y' is the ordinate of the rubbing film image to be discriminated after rotation, such as image 3 As shown, it is a schematic diagram of counterclockwise rotation.
[0048] When the rubbing film image to be discriminated is rotated clockwise, coordinate transformation is performed according to the following formula:
[0049] x'=x·cos(a)+(h-y)/h·y·sin(a)
[0050] y′=ycos(a)+x·sin(a)
[0051]Among them, x is the abscissa of the rubbing film image to be screened before rotation, y is the ordinate of the rubbing film image to be screened before rotation, a is the angle between the rubbing film image to be screened before rotation and the original VIN code rubbing film image difference; h is the height of the rubbing film image to be discriminated, x' is the abscissa of the rubbing film image to be discriminated after rotation, and y' is the ordinate of the rubbing film image to be discriminated after rotation. like Figure 4 Shown is a schematic diagram of a clockwise rotation.
[0052] Step S303, trim the original VIN code rubbing film image and the scaled and rotated rubbing film image to be screened, so that the two are of equal width and height, so as to obtain the original VIN code rubbing film VIN code character image and the image to be screened. The rubbing film VIN code character image.
[0053] Step S4, the images are combined and superimposed, and the original VIN code rubbing film VIN code character image and the VIN code character image of the rubbing film to be screened are combined and superimposed with the screening line as the boundary, and the original VIN code rubbing film VIN code characters are displayed above the screening line. The image below the screening line shows the VIN code character image of the rubbing film to be screened. like Figures 5a-5c As shown, the discrimination line is a straight line.
[0054] In step S5, the screening result is obtained, and the screening line is adjusted according to certain rules to perform scanning screening to obtain the screening result. Arbitrary translation and rotation of the screening line, if the original VIN code rubbing film VIN code character image on both sides of the screening line and the VIN code character image of the rubbing film to be screened can be aligned and reconstructed into the same VIN code character image, the results are judged to be consistent ; otherwise, the judgment results are inconsistent, and the system prompts an exception. After the original rubbing film image is normalized with the image to be discriminated, a discriminant line that can be translated and rotated arbitrarily is automatically generated, such as Image 6 As shown, the VIN code standard image and the image to be discriminated display opposite parts along the two sides of the discriminating line, and the VIN code characters of the opposite part are aligned along the discriminating line and reconstruct the same character.
[0055] The invention provides a computer-aided identification method for the VIN code rubbing films of motor vehicles. Assuming that two motor vehicle VIN code rubbing films are obtained from the same motor vehicle at different times, then the two VIN code rubbing films are both true, and the two VIN code rubbing films are both true. Each corresponding character in the Zhang Tuo printing film has the same characteristics, and the various visual characteristics of the VIN code area in the image are consistent. After aligning the images, if any inconsistent areas are found, a VIN code is determined to be forged.
[0056] The present invention also provides a screening system for realizing the above screening method, comprising:
[0057] The file extraction module is used to scan the original VIN code rubbing film and the rubbing film to be screened and save it as an image file in the same format, and extract and open the original VIN code rubbing film image and the rubbing film image to be screened; Features The point pair extraction module is used to extract the VIN code feature points located at the same position in the VIN code character area in the original VIN code rubbing film image and the rubbing film image to be screened respectively, forming a set of feature point pairs, and extracting another feature point in the same way. A set of feature point pairs; the image processing module is used to perform normalized image display on the original VIN code rubbing film image and the VIN code character area of the rubbing film image to be discriminated according to the positions of the two sets of feature point pairs, and obtain the original image. The VIN code character image of the VIN code rubbing film and the VIN code character image of the rubbing film to be screened, and the original VIN code rubbing film VIN code character image and the VIN code character image of the rubbing film to be screened are combined and superimposed on the boundary of the screening line ; The screening result acquisition module is used to adjust the screening line for scanning screening according to certain rules, and obtain screening results.
[0058] The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.
