如何得到车牌识别的字体？

[赵磊]

车牌识别字体
文章来源：www.voicing.cn
作者：赵磊
时间：2009.04

车牌识别软件需要车牌的字体信息。 作者根据《GA36-2007中华人民共和国机动车号牌》 编写了车牌字体模块。
整个模块只有一个入口函数：
bool LPRFontGet(char character,int x,int y)
在本文稍后的代码中前半部分就是这个函数的实现。 后半部分是使用这个函数的一个例子。
LPRFontGet 的功能是取得字符character在(x,y)坐标的二值像素。
输入参数：
character
需要获取字体的字符。取值范围包括数字： 0,1,2,3,4,5,6,7,8,9 和英文字母：A,B,C,D,E,F,G, H,I,J,K,L,M,N, O,P,Q,R,S,T, U,V,W,X,Y,Z。 注意，character并不区分大小写。
x
需要获取字体的x坐标。 取值范围是0~(LPT_FONT_WIDTH-1)。 LPT_FONT_WIDTH 是宏定义，目前的值是16。
y
需要获取字体的y坐标。 取值范围是0~(LPT_FONT_HEIGHT-1)。 LPT_FONT_HEIGHT 是宏定义，目前的值是LPT_FONT_WIDTH的二倍，即32。
返回值：
当输入参数合法时， 如果点(x,y)是字符上的点，LPRFontGet返回true， 否则返回false。
当输入参数非法时，LPRFontGet返回false。
注意：
1、字符1比较特殊，目前的返回值全是true。 这里并没有计算其左右的空白。 因为识别字符时， 也需要去掉图片上字符的上下左右空白。
2、LPRFontGet 本身的实现是一个类似于二值位图的数据结构， 字体信息保存在mask中；所以不需要添加任何字体文件。 其中的mask是静态常量，效率高。
3、不可以使用普通的字体，作为车牌识别的字体。
代码：
#define LPT_FONT_WIDTH 16
#define LPT_FONT_HEIGHT (LPT_FONT_WIDTH*2)
bool LPRFontGet(char character,int x,int y)
{
static const int mask[][LPT_FONT_WIDTH*LPT_FONT_HEIGHT/(sizeof(int)*8)]=
{
{0x7ffe7ffe,0x7ffe7ffe,0x3e003c00,0x0f001f00,0x07800f80,0x03e003c0,0x0ff007f0,0x3e401fe0,
0x70007800,0x70007000,0xf000f000,0x700ff000,0x700e700f,0x7c3e781e,0x1ff83ffc,0x03800ff0},
{0x3c003c00,0x3e003c00,0x3f003e00,0x3f003f00,0x3f803f80,0x3fc03fc0,0x3de03de0,0x3cf03ce0,
0x3c783c70,0x3c383c78,0x3c1e3c1c,0xffff3c1e,0xffffffff,0x3c00ffff,0x3c003c00,0x3c003c00},
{0x7ffe7ffe,0x7ffe7ffe,0x001e001e,0x001e001e,0x001e001e,0x001e001e,0x1ffe07fe,0x3e7e3ffe,
0x7000781c,0x70007000,0xf000f000,0x700f7000,0x700e700f,0x7c3e781e,0x1ff83ffc,0x03800ff0},
{0x0e000000,0x0f001f00,0x07c00780,0x01e003e0,0x00f000f0,0x00780078,0x003c0038,0x0ffc07dc,
0x3ffe3ffe,0x781e7c3e,0x700f700f,0xf00ff00f,0x701e700f,0x7e7c781e,0x1ff83ffc,0x03c00ff0},
{0xffffffff,0xffffffff,0x7800f000,0x3c007800,0x3c003c00,0x1e001c00,0x1e001e00,0x0f000f00,
0x0f000f00,0x07000700,0x07800780,0x07800780,0x03800380,0x03800380,0x03800380,0x03800380},
{0x0fe00180,0x3ff81ff8,0x783c3e7c,0x701e701e,0x700e700e,0x781e701e,0x3e7c783c,0x1ff81ff8,
0x3ffc3ffc,0x781e7c3e,0xf00f700e,0xf00ff00f,0x701f700f,0x7c3e781e,0x1ffc3ffc,0x03c00ff8},
{0x07f00180,0x3ffc1ff8,0x7c1e3e7c,0x700e701e,0xf00f700f,0x700e700f,0x781e781e,0x7ffc7e7c,
0x7ff07ff8,0x3c003c80,0x1e003c00,0x0f001e00,0x07800f80,0x01e003c0,0x00f801f0,0x00200078},
{0x03c003c0,0x03c003c0,0x07e007e0,0x07e007e0,0x07e007e0,0x0ff00ff0,0x0e700ff0,0x1e780e70,
0x1e781e78,0x1c381e78,0x3c383c38,0x3ffc3c3c,0x7ffc3ffc,0x781e7ffe,0x701e781e,0x0003701e},
{0x07ff003f,0x3fff1fff,0x780f7fff,0x700f700f,0x700ff00f,0x780f700f,0x3fff7c0f,0x3fff1fff,
0x780f3e0f,0x700f700f,0x700f700f,0x700f700f,0x700f700f,0x7c0f780f,0x1fff3fff,0x00ff0fff},
{0x0ff00380,0x3ffc1ff8,0x781e7c7e,0x700f700f,0x000ff00f,0x000f000f,0x000f000f,0x000f000f,
0x000f000f,0x000f000f,0xf00f000f,0xf00ff00f,0x700e700f,0x7c3e701e,0x1ff83ffc,0x01800ff0},
{0x0fff03ff,0x3fff1fff,0x780f7c0f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,
0xf00ff00f,0x700ff00f,0x700f700f,0x700f700f,0x700f700f,0x7c0f780f,0x1fff3fff,0x01ff0fff},
{0x7fff7fff,0x7fff7fff,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x3fff3fff,
0x000f3fff,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0xffffffff,0xfffeffff},
{0x7fff7fff,0x7fff7fff,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x3fff3fff,
0x3fff3fff,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000e000f},
{0x0fe00000,0x3ffc1ff8,0x781e7e7c,0x700f700e,0x000f000f,0x000f000f,0xff8f000f,0xff8fff8f,
0xf00fff8f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ef00f,0x783e701e,0x3ff83ffc,0x01801ff0},
{0x700f700e,0x700f700f,0x700f700f,0x700f700f,0x700f700f,0x700f700f,0xf00f700f,0xffffffff,
0xffffffff,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0x700ff00f},
{0xffffffff,0xffffffff,0x0fe07ffe,0x0fe00fe0,0x0fe00fe0,0x0fe00fe0,0x0fe00fe0,0x0fe00fe0,
0x0fe00fe0,0x0fe00fe0,0x0fe00fe0,0x0fe00fe0,0x0fe00fe0,0x0fe00fe0,0xffffffff,0xffffffff},
{0xf0007000,0xf000f000,0xf000f000,0xf000f000,0xf000f000,0xf000f000,0xf000f000,0xf000f000,
0xf000f000,0xf000f000,0xf000f000,0xf000f000,0x700e700e,0x7c3c781e,0x3ff83ffc,0x01800ff0},
{0x700e000e,0x7c0e780e,0x1e0e3c0e,0x0f0e1e0e,0x078e0f0e,0x07ce078e,0x07ee07ce,0x0ffe0ffe,
0x0e7e0ffe,0x1e3e0e3e,0x1c1e1e1e,0x3c0e1c0e,0x380e3c0e,0x780e380e,0x700f700f,0x000e700f},
{0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,
0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0xffffffff,0xfffeffff},
{0xf01ff00e,0xf81ff81f,0xfc3ffc3f,0xfe7ffe7f,0xffefffff,0xf7cff7ef,0xf18ff3cf,0xf10ff18f,
0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ef00f},
{0xf00f700f,0xf01ff01f,0xf03ff03f,0xf07ff03f,0xf0fff07f,0xf0fff0ff,0xf1eff1ef,0xf3cff3cf,
0xf78ff3cf,0xff0ff78f,0xff0fff0f,0xfe0fff0f,0xfc0ffe0f,0xf80ffc0f,0xf80ff80f,0x6000f00f},
{0x0ff00180,0x3ffc1ff8,0x781e3e3e,0x700f700f,0x700f700f,0x700f700f,0x700f700f,0x700f700f,
0x700f700f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0x700ff00f,0x7c3e781e,0x1ff83ffc,0x01800ff0},
{0x0fff01ff,0x3fff1fff,0x780f7e0f,0x700f700f,0xf00f700f,0x700ff00f,0x780f700f,0x3fff7e0f,
0x07ff1fff,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f,0x000f000f},
{0x07f00180,0x3ffc1ff8,0x781e3e3e,0x700e780e,0x700f700f,0x700f700f,0x700f700f,0x700e700e,
0x700e700e,0x700e700e,0x73ce73ce,0xf78e738e,0x7f0ef70e,0x7e3e7e1e,0x3ff83ffc,0x01007ff0},
{0x07ff007c,0x3fff1fff,0x780f3e0f,0x700f780f,0xf00f700f,0x700ff00f,0x780f700f,0x3fff7e0f,
0x07ff1fff,0x0f0f078f,0x0e0f0f0f,0x1e0f0e0f,0x3c0f1e0f,0x380f3c0f,0x780f780f,0xf00f700f},
{0x07f00180,0x1ffc0ff8,0x3c1e3e7c,0x780e781e,0x000e700e,0x001e000e,0x007c001e,0x1ff807f8,
0x7c003fe0,0x70007800,0x70007000,0x7000f000,0x701e700f,0x3c3e781e,0x1ff83ffc,0x01800ff0},
{0xffff03ff,0xffffffff,0x03c003c0,0x03c003c0,0x03c003c0,0x03c003c0,0x03c003c0,0x03c003c0,
0x03c003c0,0x03c003c0,0x03c003c0,0x03c003c0,0x03c003c0,0x03c003c0,0x03c003c0,0x03c003c0},
{0xf00e7000,0xf00ef00e,0xf00ef00e,0xf00ef00e,0xf00ef00e,0xf00ef00e,0xf00ef00e,0xf00ef00e,
0xf00ef00e,0xf00ef00e,0xf00ef00e,0xf00ef00e,0x700ef00e,0x7c3c781e,0x3ff83ffc,0x03c01ff0},
{0xf00e000e,0x701e700e,0x781e701e,0x781c781e,0x3c3c383c,0x3c3c3c3c,0x1c381c38,0x1e781e78,
0x0e781e78,0x0ff00f70,0x0ff00ff0,0x07f007f0,0x07e007e0,0x03e007e0,0x03e003e0,0x01c003c0},
{0xf10ef00f,0xf10ef10e,0x718ef18e,0x739e718e,0x73de73de,0x77de73de,0x77fe77de,0x7ffe77fe,
0x7ffc7ffe,0x7efc7ffc,0x7efc7efc,0x7e7c7e7c,0x3c7c7e7c,0x3c3c3c7c,0x3c3c3c3c,0x383c383c},
{0x701ef00e,0x781c701e,0x3c3c383c,0x1e783c38,0x0ef01e78,0x0ff00ef0,0x07e00fe0,0x03c007c0,
0x03c003c0,0x07e007c0,0x0ff00fe0,0x1e700ef0,0x3c381e78,0x3c3c3c3c,0x781e781c,0xf00f701e},
{0x781ef00f,0x783c781e,0x3c783c3c,0x1ef81e78,0x0ff00ef0,0x07e00fe0,0x07c007c0,0x03800380,
0x03800380,0x03800380,0x03800380,0x03800380,0x03800380,0x03800380,0x03800380,0x03800380},
{0x7fff7fff,0x7fff7fff,0x38007800,0x1c003c00,0x0e001e00,0x0f000e00,0x07800700,0x03c00380,
0x01e001c0,0x00f001e0,0x007800f0,0x00380078,0x003c003c,0x001e001e,0x7ffe7ffe,0xfffefffe},
};
int character_index;
if(character>=0&&character<=9)
character_index=character-0;
else if(character>=a&&character<=z)
character_index=character-a+10;
else if(character>=A&&character<=Z)
character_index=character-A+10;
else
return false;
if(x<0)
return false;
if(x>=LPT_FONT_WIDTH)
return false;
if(y<0)
return false;
if(y>=LPT_FONT_HEIGHT)
return false;
int int_index;
int_index=y*LPT_FONT_WIDTH+x;
int bit_index;
bit_index=int_index%(sizeof(int)*8);
int_index/=(sizeof(int)*8);
if(mask[character_index][int_index]&(1<<bit_index))
return true;
else
return false;
}
读者如果正在研发车牌识别系统的话， 还可以参考一下绿睿车牌识别。 其识别率和识别速度还是不错的。 目前这款高性能软件市场参考价只有￥210。

[赵磊]

上面那个不全呀。
static const int mask[][LPT_FONT_WIDTH*LPT_FONT_HEIGHT/(sizeof(int)*8)]=
{
{0x0ff00180,0x3ffc1ff8,0x781e7e7e,0xf00f700f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,
0xf00ff00f,0xf00ff00f,0xf00ff00f,0xf00ff00f,0x700ff00f,0x7c3e781e,0x3ff83ffc,0x07c01ff0},
{0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,
0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff},
{0x07e00100,0x3ff81ff0,0x783e7e7c,0xf00e701e,0xe000e008,0x70007000,0x3c007800,0x1e003c00,
0x0f000f00,0x03c00780,0x01e003e0,0x00f800f0,0x003c0078,0x001e003e,0x7fff7fff,0x7fff7fff},
{0x7ffe7ffe,0x7ffe7ffe,0x3e003c00,0x0f001f00,0x07800f80,0x03e003c0,0x0ff007f0,0x3e401fe0,
0x70007800,0x70007000,0xf000f000,0x700ff000,0x700e700f,0x7c3e781e,0x1ff83ffc,0x03800ff0},
{0x3c003c00,0x3e003c00,0x3f003e00,0x3f003f00,0x3f803f80,0x3fc03fc0,0x3de03de0,0x3cf03ce0,
0x3c783c70,0x3c383c78,0x3c1e3c1c,0xffff3c1e,0xffffffff,0x3c00ffff,0x3c003c00,0x3c003c00},
{0x7ffe7ffe,0x7ffe7ffe,0x001e001e,0x001e001e,0x001e001e,0x001e001e,0x1ffe07fe,0x3e7e3ffe,
0x7000781c,0x70007000,0xf000f000,0x700f7000,0x700e700f,0x7c3e781e,0x1ff83ffc,0x03800ff0},
{0x0e000000,0x0f001f00,0x07c00780,0x01e003e0,0x00f000f0,0x00780078,0x003c0038,0x0ffc07dc,
0x3ffe3ffe,0x781e7c3e,0x700f700f,0xf00ff00f,0x701e700f,0x7e7c781e,0x1ff83ffc,0x03c00ff0},
{0xffffffff,0xffffffff,0x7800f000,0x3c007800,0x3c003c00,0x1e001c00,0x1e001e00,0x0f000f00,
0x0f000f00,0x07000700,0x07800780,0x07800780,0x03800380,0x03800380,0x03800380,0x03800380},
{0x0fe00180,0x3ff81ff8,0x783c3e7c,0x701e701e,0x700e700e,0x781e701e,0x3e7c783c,0x1ff81ff8,
0x3ffc3ffc,0x781e7c3e,0xf00f700e,0xf00ff00f,0x701f700f,0x7c3e781e,0x1ffc3ffc,0x03c00ff8},
{0x07f00180,0x3ffc1ff8,0x7c1e3e7c,0x700e701e,0xf00f700f,0x700e700f,0x781e781e,0x7ffc7e7c,

[magicwei007]

麻烦问一下这段代码是干什么用的啊？能显示出车牌上面的字体吗？

[zhoujk]

没研究过，不过应该不会太难，如果不同类型的车牌的字体不一样的话，应该这么解决，先从车牌的颜色判断出车牌对应的类型，然后将《GA36》上对应的字体类型提出来就行了吧。