一、車牌識別技術(shù)原理

1、車牌識別系統(tǒng)框架 真地車牌識別系統(tǒng)采用高度模塊化的設(shè)計(jì)，真地將車牌識別過程的各個(gè)環(huán)節(jié)各自作為一個(gè)獨(dú)立的模塊，真地采用國際領(lǐng)先的計(jì)算機(jī)智能算法技術(shù)，首先通過攝像頭提取車牌視頻圖像，對獲取的每一幀圖像，真地利用最新的高效視頻檢測技術(shù)對車牌進(jìn)行定位和跟蹤，車牌識別攝取從中自動提取車牌圖像，然后經(jīng)過車牌精確定位、切分和識別模塊準(zhǔn)確地自動分割和識別字符，得到車牌的全部字符信息以及顏色信息。系統(tǒng)框架如圖所示： The real license plate recognition system uses a highly modular design. It really takes each link of the license plate recognition process as an independent module. It really adopts the international leading computer intelligent algorithm technology. First, it extracts the license plate video image through the camera. For each frame of image, it really uses the latest high efficiency. Video detection technology locates and tracks the license plate, and the license plate image is automatically extracted from the license plate recognition. Then, the characters are automatically segmented and recognized accurately by the accurate license plate location, segmentation and recognition module, and the whole character information and color information of the license plate are obtained. The system frame is shown in the figure: 2、車牌識別車牌定位模塊 整個(gè)停車場智能系統(tǒng)車牌定位模塊是一個(gè)十分重要的環(huán)節(jié)，是后續(xù)環(huán)節(jié)的基礎(chǔ)，其準(zhǔn)確性對整體系統(tǒng)性能的影響巨大。本系統(tǒng)實(shí)現(xiàn)了一種完全基于學(xué)習(xí)的多種特征融合的車牌定位新算法，適用于各種復(fù)雜的背景環(huán)境和不同的攝像角度。真地車牌識別系統(tǒng)同步內(nèi)置的區(qū)域設(shè)置功能，可以很大程度上減少外部環(huán)境對于車牌識別的干擾，達(dá)到最好的識別效率。 The license plate positioning module of the whole parking intelligent system is a very important link, is the basis of the follow-up link, its accuracy has a great impact on the overall system performance. This system implements a new license plate location algorithm based on learning and multi-feature fusion, which is suitable for various complex background environments and different camera angles. The real license plate recognition system synchronizes the built-in area setting function, can greatly reduce the external environment for the license plate recognition interference, to achieve the best recognition efficiency. 3、車牌矯正及定位模塊 車牌識別受拍攝條件的限制，圖像中的車牌總不可避免的存在一定的傾斜，車牌識別需要一個(gè)矯正和定位環(huán)節(jié)來進(jìn)一步提高車牌圖像的質(zhì)量，為切分和識別模塊做準(zhǔn)備。真地車牌識別系統(tǒng)使用獨(dú)創(chuàng)的精心設(shè)計(jì)的快速圖像處理濾波器，計(jì)算速度快，利用車牌整體信息，避免了局部噪聲帶來的影響，另一個(gè)優(yōu)點(diǎn)就是通過對多個(gè)中間結(jié)果的分析還可以對車牌進(jìn)行定位，進(jìn)一步減小非車牌區(qū)域的影響。真地車牌識別系統(tǒng)較之其他公司的車牌識別系統(tǒng)，對于傾斜車牌圖片的支持要更多，一般的車牌識別軟件，支持的傾斜角度是±5°，該車牌識別軟件，能支持±45°的傾斜角度，并且通過內(nèi)部傾斜校正算法，不會因?yàn)閮A斜角度的增加而降低識別率。 The license plate recognition is limited by the shooting conditions, the license plate in the image always inevitably exists a certain tilt, the license plate recognition needs a correction and positioning link to further improve the quality of the license plate image, in order to prepare for segmentation and recognition module. True Land License Plate Recognition System uses original and elaborately designed fast image processing filter, which has fast calculation speed and avoids the influence of local noise by utilizing the overall information of the license plate. Another advantage is that it can locate the license plate through the analysis of many intermediate results and further reduce the influence of non-license plate area. . True Land License Plate Recognition System has more support for tilted license plate pictures than other license plate recognition systems. General license plate recognition software supports tilt angle of +5 degrees. This license plate recognition software can support tilt angle of +45 degrees, and through internal tilt correction algorithm, it will not increase tilt angle. Increase and decrease the recognition rate. 4、車牌切分模塊 車牌切分模塊利用車牌文字的灰度、顏色、邊緣分布等各種特征，能較好地抑制車牌周圍其他噪聲的影響，并能容忍一定傾斜角度的車牌。 The license plate segmentation module makes use of the gray level, color, edge distribution and other features of the text of the license plate, which can better suppress the influence of other noise around the license plate, and can tolerate a certain tilt angle of the license plate. 5、車牌識別模塊 在車牌識別模塊中，采用了多種識別模型相結(jié)合的方法，構(gòu)建了一種層次化的字符識別流程，有效地提高了字符識別的正確率。另一方面，在字符識別之前，使用計(jì)算機(jī)智能算法對字符圖像進(jìn)行了前期處理，不僅保留了圖像信息，而且提高了圖像質(zhì)量和相似字符的可區(qū)分性，保證了字符識別的可靠性準(zhǔn)確性。 In the license plate recognition module, a hierarchical character recognition process is constructed by combining several recognition models, which effectively improves the accuracy of character recognition. On the other hand, before character recognition, the computer intelligent algorithm is used to pre-process the character image, which not only retains the image information, but also improves the image quality and distinguishability of similar characters, ensuring the reliability and accuracy of character recognition. 真地車牌識別行業(yè)領(lǐng)導(dǎo)者，專業(yè)研發(fā)停車場系統(tǒng)10年以上，一直以創(chuàng)新穩(wěn)定的技術(shù)，服務(wù)于全球各大停車場，使通行更安全，方便快捷。