PHP扩展之 Imagick安装

前两天研究php中的 imagick 扩展的时候，突发奇想实现的一个小功能感觉挺有意思，在这里记录一下：

将一张image图片转化为字符串的形式，先上一张效果图。（运行笔记中的代码需要先安装 php_imagick 扩展 教程可以看这里：php扩展之 imagick安装）

                                                                                                                                              
                                                                                                                                              
                                                                                                                                              
                                                          ,;+:               ,+:.                                                             
                                                   .flllllllllf             flllllllllf.                                                      
                                                .llllclllllllcl*           *llllllllllllll.                                                   
                                              .lllllllllllllllcl.         .lllllllllllllllll.                                                 
                                             +llllllllllllllcllll         lllllllllllllllllll*                                                
                                            tllllllllllllllllllll:       :llllllllllllllllllllt                                               
                                           .llllllllllllllllllllll       llllllllllllllllllclll:                                              
                                           lclllllllllllllllllllll.     .lllllllllllllllllclllll                                              
                            +ll.           lllllllllllllllllllllllt     tlllllllllllllllllllllll           .ll*                               
                          .lllclt          llllllllllllllllllllllll     llllllllllllllllllllllll          tlllll,                             
                         fllllllll.        flllllllllllllllllllllll     lllllllllllllllllllllllf        .llllllllf                            
                        lllllllllllf       ;lllllllllllllllllllllll:   :lllllllllllllllllllllll;       tllcllllllll.                          
                      .llllllllllllll.      lllllllllllllllllllllllt   tlllllllllllllllllllllll      .llllllllllllll,                         
                      llllllllllllllll*     ,llllllllllllllllllllllf   fllllllllllllllllllllll:     *lllllllllllllllc.                        
                     lllllllllllllllllll     fclllllllllllllllllllll   lllllllllllllllllcllllf     lllclllllllllllllll                        
                    :lcllllllllllllllllll:    llllllllllllllllllllll   lllllllllllllllllcllll    ,llllllllllllllllllll:                       
                    flllllllllllllllllllllf    lllllllllllllllllllll   lllllllllllllllllllll    flclllllllllllllllllllf                       
                    flllllllllllllllllllllll    lcllllllllllllllllll   llllllllllllllllllll.   lllllllllllllllllllllllf                       
                    :lllllllllllllllllllllllc,  .lllllllllllllllllll   lllllllllllllllllll.  ,llllllllllllllllllllllll:                       
                     lllllllllllllllllllllllllt  .llllllllllllllllll   llllllllllllllllll,  *lllllllllllllllllllllllll                        
                      llllllllllllllllllllllllll  .lllllllllllllllll   lllllllllllllllll.  llllllllllllllllllllllllll                         
                       llllllllllllllllllllllllll.  llllllllllllllll   lllllllllllllllc.  lllcllllllllllllllllllllll                          
             +.         ,lllllllllllllllllllllllll, .lllllllllllllll   lllllllllllclll  .lllllllllllllllllllllllll,         ,*                
            :llclf        ,llllllllllllllllllllllcl+  llllllllllllll   llllllllllllll  ;cllcllllllllllllllllllll,       .fllll;               
            fllllllll+       fllllllllllllllllllllllt  fllllllllllll   llllllllllllf  *lllllllllllllllllllllll       +lllllllll               
            lllllllllllll,     :llllllllllllcllllllllf  +cllllllllll   lllllllllll+  flllllllllllllclllllll:     ,lllllllllllll               
            llllllllllllllllt     +llllllllclcllllcllll  ,lllllllllf   flllllllll,  llllllllllllllllllll+     tllllllllllllllll               
            +lllllllllllllllllll:    ;llllllllllllllllll  .llllllllt   tllllllll   lllcllllllllllllll;    ;lllllllllllllllllll*               
             llllllllllllllllllllllf    ,llllllllllllllll   fllllll;   ;lllllll   llllllllllllllll,   .flcllllllllllllllllllll                
             ;llllllllllllllllllcllllll:   .flllllllllclll   +lllll.    lclll+   lllllllllllllf.   :lllllllllllllllllllllllll;                
              +llllllllllllllllllcllllllllt   .:lllllllllll   .clll     llll.   lllllllllll:    tlllllllllllllllllllllllllll*                 
               ,llllllllllllllllllllllllllllll,    tclllllll    lll     lll    llllllllt    ,llllllllllllllllllllllllllllll:                  
                 flllllllllllllllllllllllllclllll;    .flllll    ,:     ::    lllllf.    ;lllclllllllllllllllllllllllllllf                    
                   fllllllllllllllllllllllllllllllllt     ,lll               fll,     tlllllllllllllllllllllllcllllllllf                      
                     ,lllllllllllllllllllllllllllllllllf                           fllllllllllllllllllllllllcllllllll,                        
                         :flllllllllllllllllllllcllllllllll                     fcllllllllllllllllllllllllllllllf:                            
                                           .    ..  . ...                        .  ....                                                      
                               ,,:;++*ttffffflllllllllllll;                     :cllllllllllllfffftt**++::,.                                  
                       fllllllllllllllllllllllllllclllll:                         :lllllllllllllllllllllllllllllllll                          
                        +lllcllllllllllllllllllllllll;                               ;llllclllllllllllllllllllllll+                           
                          flllllllllllllllllllllll:                                     :llllllllllllllllllllllll                             
                            flllllllllllcllllcl,                                           ,llllllllllllllllllf                               
                              .flllllllllll;                                                   ;llllclllllll.                                 
                                                                                                                                              
                                                                                                                                              
                                                                                                                                              
                                                                                                                                              
                                                                                                                                              
                                                                                                                                              
            +ggg+        fg0g,    +ggg+        lggg.        .ggggt      tg0g*       l0gg;       gggg   ;ggg0ggggg00ggl    ,gggt               
            +ggg+        l0gg,    +ggg+        lggg.        gg00gg+      c0g0,     +g0ggg      tg0g;   ;gggltffffffff*    ,gggt               
            +ggg*        fggg,    +ggg+        lggg.       cgggfg0g;     ,gggc    .ggg0ggt    :0ggf    ;ggg*              ,gggt               
            +ggg*........lggg,    +ggg+        lggg.      lgg0. lgg0,     *ggg+   lgggtggg:   gggg     ;gggf++++++,       :gggt               
            +gggg0g0ggg0ggg0g,    +ggg+        lgg0.     tg0g:   cggg.     c0gg. +0gg: cggg  tggg:     ;gg0ggggg0g*       ,gggt               
            +gggl********c0gg,    +ggg*        cgg0.    *gg0*,,,,:gggg     .gggl.0ggt  ,g0gt,gggt      ;g0g*......        ,gggt               
            +ggg*        lggg,    ,gggg       :gggc    ;g0ggg0ggggg0ggc     +0g0gggc    +ggggg0c       ;0gg+              ,gggt               
            +ggg+        fggg,     *g0ggf:.,;cggg0,   :gggl;;;;;;;;*0ggl     lgg00g,     lggggg,       ;0ggt,,,,,:,::,    ,gggt               
            +ggg+        fggg,      ,gg0000gg0ggl    .0ggc          *g00t     0ggg*       0g0g+        ;ggggggggg0gggg.   ,g0gt               
            .,,,.        ,,,:           .,:,,.       ....            ....      ...         ...          ..............     ...                
                                                                                                                                              
                                                                                                                                              
                                                                                                                                              

 

                       

原图：

 

<?php
/**
* 图片转换为字符图
* @param string $imagepath 图片地址
* @param int $width x轴方向缩放比例
* @param int $height y轴方向缩放比例
* @return string 生成的字符串图
*/
function img2string($imagepath,$width=1,$height=1)
{
    //检查是否安装 php_imagick 扩展
    if(!extension_loaded("imagick")){
        exit("请先安装 imagick 模块");
    }
    $imagick = new \imagick(realpath($imagepath));
    //将生成的imagick对象转化为一个像素迭代器，可以从该迭代器中获取没个像素的 rgb 的值。不知道什么是rgb的请问度娘
    $imageiterator = new \imagickpixeliterator($imagick);
     $str='o80gclft*+;:,. ';
    foreach ($imageiterator as $rows => $pixels) {
            if($rows%$width == 1 || $width == 1){
                echo "\n";
                foreach ($pixels as $column => $pixel) {
                    if($column%$height == 1 || $height == 1){
                        //灰度计算公式  某个像素点的灰度值 = 红色值*0.3 + 绿色值 * 0.59 + 蓝色值 * 0.11
                        $gray = $pixel->getcolor()['r']*0.3 + $pixel->getcolor()['g']*0.59 + $pixel->getcolor()['b']*0.11;
                        //由于 rgb 三原色的数值范围在 [0,255] 所以求出的灰度值的范围也是 [0,255],所以我们计算像素的 "饱和度" = 灰度值/255;
                        $r = $gray/255;
                        //根据像素的 "饱和度" 选择合适的字符
                        $offset=(int)ceil($r*(strlen($str)-1));    
                        if($offset==(strlen($str)-1)){
                            echo " ";
                        }else{
                            echo $str[$offset];  
                        }
                    }         
                }
                $imageiterator->synciterator();
            }    
    }
}

img2string('huawei.jpg',2,1);