【導(dǎo)讀】車牌區(qū)域定位、車牌字符分割和車牌字符識(shí)別。本文針對(duì)車牌自動(dòng)識(shí)別系統(tǒng)中關(guān)鍵技術(shù)之。一的車牌字符分割部分做了深入的研究。開閉運(yùn)算、去除邊緣、去除圓點(diǎn)等。實(shí)驗(yàn)結(jié)果表明，這兩種方法可以對(duì)車牌字符進(jìn)行分割，但效果都不是很理想?？蛇_(dá)到較好的效果。

　　

【正文】 %%%%%%% SE=strel(39。disk39。,fix(y/45))。%創(chuàng)建一個(gè)平坦的圓盤形結(jié)構(gòu)元素 I2=imopen(I1,SE)。%取圓盤形的開運(yùn)算 subplot(2,2,3)。%圖一的第三幅圖 imshow(I2),title(39。開運(yùn)算后圖像 39。)。 SE=strel(39。diamond39。,fix(y/140))。%創(chuàng)建一個(gè)平坦的菱形結(jié)構(gòu)元素 I3=imclose(I2,SE)。%取菱形結(jié)構(gòu)的閉運(yùn)算 subplot(2,2,4)。%圖一的第四幅圖 imshow(I3),title(39。閉運(yùn)算后圖像 39。)。 I4=double(I3)。%變?yōu)殡p精度 %%%%%%%%%%%%%%%計(jì)算像素 %%%%%%%%%%%%%%% %%%%%%%計(jì)算行像素 %%%%%%%% Y1=zeros(y,1)。 附錄 for i=1:y for j=1:x if(I4(i,j,1)==1) Y1(i,1)= Y1(i,1)+1。%計(jì)算 I3 第 j 列有幾個(gè)一 end end end figure(2)。 plot(Y1,0:y1),title(39。行方 向像素點(diǎn)灰度值累計(jì)和 39。),xlabel(39。累計(jì)像素量 39。),ylabel(39。行值 39。)。 %%%%%去除行方向邊框 %%%%%%%%%% Py0=fix(y/2)。 Py1=fix(y/2)+1。 while ((Y1(Py0,1)=30)amp。amp。(Py02)) Py0=Py01。%找到去除邊框后上邊的位置 end while ((Y1(Py1,1)=30)amp。amp。(Py1y)) Py1=Py1+1。%找到去除邊框后下邊的位置 end Z1=I4(Py0:Py1,:,:)。%將二值圖像上下邊框去除 figure(3)。 imshow(Z1),title(39。將二值圖像上下邊框去除后圖像 39。)。%將二值圖像上下邊框去除后圖像顯示出來(lái) [y,x,z]=size(Z1)。%計(jì)算此時(shí)圖像的大小 %%%%%%%%%%%%計(jì)算列像素 %%%%%%%%%% X1=zeros(1,x)。 for j=1:x for i=1:y if(Z1(i,j,1)==1) X1(1,j)= X1(1,j)+1。%計(jì)算 I3 第 j 列有幾個(gè)一 end end end figure(4)。 附錄 plot(0:x1,X1),title(39。列方向像素點(diǎn)灰度值累計(jì)和 39。),xlabel(39。列值 39。),ylabel(39。累計(jì)像素量 39。)。 %%%%%%%%去除垂直邊框 %%%%%%%%% x1=fix(x/2)+1。 for i=1:5 while (i~=5) while ((X1(1,x1)=15)amp。amp。(x1x)) x1=x1+1。%找到去除邊框后右邊的位置 end i=i+1。 while ((X1(1,x1)15)amp。amp。(x1x)) x1=x1+1。%從車牌中間開始尋找字符間隙，直到找到第四個(gè)間隙為止，即找到去除邊框后車牌右邊的位置 end end end x0=fix(x*45/440)。%找到第一個(gè)字符的位置 for i=1:2 while (i~=2) while ((X1(1,x0)=5)amp。amp。(x02)) x0=x01。%從車牌的第一個(gè)字符開始尋找第一個(gè)字符間隙，找到去除邊框左邊的位置 end i=i+1。 while ((X1(1,x0)5)amp。amp。(x01)amp。amp。i~=2) x0=x01。%找到去除邊框后左邊的位置 end end end Z2=Z1(:,x0:x1,:)。%將二值圖像左右邊框去除 figure(5)。 imshow(Z2),title(39。將二值圖像垂直邊框去除后圖像 39。)。%將二值圖像垂直邊框去除后圖像顯示出來(lái) Px0=1。 附錄 Px1=1。 %%%%%%%%%再次計(jì)算列方向像素 %%%%%%%%% [y,x,z]=size(Z2)。%計(jì)算此時(shí)圖像的大小 X1=zeros(1,x)。 for j=1:x for i=1:y if(Z2(i,j,1)==1) X1(1,j)= X1(1,j)+1。%計(jì)算 I3 第 j 列有幾個(gè)一 end end end %%%%%%%去除圓點(diǎn) %%%%%% [y,x,z]=size(Z2)。 Z2=double(Z2)。 x1=fix(x*110/409)。 x2=fix(x*128/409)。 for i=1:y for j=x1:x2 Z2(i,j)=0。 end end figure(6)。 imshow(Z2),title(39。去除圓點(diǎn)后圖像 39。)。 %%%%%%%%%%%%%對(duì)圖像分割 %%%%%%%%%%%%%% y=fix(x*90/409)。 %%%%%%%用投影法分割 %%%%%% for i=1:7 while ((X1(1,Px0)10)amp。amp。(Px0x)) Px0=Px0+1。%找到待分割字符左邊的位置 end Px1=Px0。 a=1。 while (((X1(1,Px1)=10)amp。amp。(Px1x))||((Px1x)amp。amp。((a/y)=))) 附錄 Px1=Px1+1。%找到待分割字符右邊的位置 a=Px1Px0。 end Z3=Z2(:,Px0:Px1,:)。%二值化圖像分割后 figure(7)。 subplot(1,7,i)。 imshow(Z3)。%將二值化圖像分割后顯示出來(lái) %%%%%%變換為標(biāo)準(zhǔn)子圖 %%%%%%%% Z4=imresize(Z3,[88 40])。%將分割后的二值圖變換為標(biāo)準(zhǔn)子圖 figure(8)。 subplot(1,7,i)。 imshow(Z4),title(39。標(biāo)準(zhǔn)子圖 39。)。%將標(biāo)準(zhǔn)子圖顯示出來(lái) Px0=Px1。 end 附錄 附錄 B英文原文及翻譯 英文原文： Design and Instrumentation of Measurement and Calibration System for Acoustic Telemetry System Abstract: The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the . Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more “fish friendly” hydroelectric facilities. The objective of this study was to design and build a Measurement and Calibration System (MCS) for evaluating the JSATS ponents, because the JSATS requires prehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The MCS consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a puter. The fully integrated MCS has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. The MCS provides accurate acoustic mapping capability in a controlled environment and automates the process that allows realtime measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The MCS has been in use since 2020 for acceptance and performance testing of, and further improvements to, the JSATS. Keywords: underwater transducers。 piezoelectric sensors。 acoustic telemetry 1. Introduction The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology that was developed by the . Army Corps of Engineers (USACE), Portland District, to evaluate the migration timing, behavior, and survival of juvenile salmonids migrating through the Federal Columbia River Power System (FCRPS) [1]. The JSATS consists of acoustic micro transmitters (or transducers)。 autonomous, cabled, or portable receivers with hydrophones (piezoelectric sensors)。 and data management and processing applications. Receivers have been deployed at large hydroelectric dams [2] and in freeflowing sections [3] of the FCRPS, as well 附錄 as throughout the estuary of the Columbia River [4]. Each micro transmitter, surgically implanted in study fish, transmits a unique binary code encoded using binary phase shift keying (BPSK) at a frequency of kHz. Its code structure includes a total of 31 bits, with 7 synchronization bits (Barker code 1110010), 16 data bits, and 8 cyclic redundancy check (CRC) bits. The micro transmitters emit this unique 31bit code at a programmed inte