PHP implementation search for similar images, _php tutorial

PHP implementation to search for similar images,

Perceptual hashing algorithm

Count < = 5 Match most similar
Count > 102 Different pictures
Var_dump (Imagehash::run ('./1.png ', './psb.jpg '));

<?phpclass Imagehash {Const File_not_found = '-1 ';  Const File_extname_illegal = '-2 ';    Private Function __construct () {} public static function run ($src 1, $src 2) {static $self;    if (! $self) $self = new Static;    if (!is_file ($src 1) | |!is_file ($SRC 2)) exit (Self::file_not_found);    $hash 1 = $self->gethashvalue ($src 1);    $hash 2 = $self->gethashvalue ($src 2);    if (strlen ($hash 1)!== strlen ($hash 2)) return false;    $count = 0;    $len = strlen ($hash 1);    for ($i = 0; $i < $len; $i + +) if ($hash 1[$i]!== $hash 2[$i]) $count + +; Return $count <= 10?  True:false;    Public Function GetImage ($file) {$extname = PathInfo ($file, pathinfo_extension);    if (!in_array ($extname, [' jpg ', ' jpeg ', ' png ', ' gif ')]) exit (Self::file_extname_illegal); $img = Call_user_func (' Imagecreatefrom '. ($extname = = ' jpg '?    ' JPEG ': $extname), $file);  return $img;    The Public Function Gethashvalue ($file) {$w = 8;    $h = 8;    $img = Imagecreatetruecolor ($w, $h); List ($src _w, $SRC _h) = getimagesize ($file);    $SRC = $this->getimage ($file);    Imagecopyresampled ($img, $src, 0, 0, 0, 0, $w, $h, $src _w, $src _h);    Imagedestroy ($SRC);    $total = 0;    $array = Array ();  for ($y = 0; $y < $h; $y + +) {for ($x = 0; $x < $w; $x + +) {$gray = (Imagecolorat ($img, $x, $y) >>        8) & 0xFF;        if (!isset ($array [$y])) $array [$y] = array ();        $array [$y] [$x] = $gray;      $total + = $gray;    }} Imagedestroy ($IMG);    $average = Intval ($total/($W * $h * 2));    $hash = "; for ($y = 0; $y < $h; $y + +) {for ($x = 0; $x < $w; $x + +) {$hash. = ($array [$y] [$x] >= $average)?      ' 1 ': ' 0 ';    }} var_dump ($hash);  return $hash; }}var_dump (Imagehash::run ('./1.png ', './psb.jpg '));

Method Two:

hash ($f); } return $isString? $result [0]: $result; The Public Function checkissimilarimg ($imgHash, $otherImgHash) {if (file_exists ($imgHash) && file_exists ($  Otherimghash) {$imgHash = $this->run ($imgHash); $otherImgHash = $this->run ($otherImgHash); } if (strlen ($imgHash)!== strlen ($otherImgHash)) return false; $count = 0; $len = strlen ($imgHash);  for ($i =0; $i < $len; $i + +) {if ($imgHash {$i}!== $otherImgHash {$i}) {$count + +; }} return $count <= (5 * $rate * $rate)? True:false; The Public Function hash ($file) {if (!file_exists ($file)) {return false;} $height = 8 * $this->rate; $width = 8 * $this ->rate; $img = Imagecreatetruecolor ($width, $height); List ($w, $h) = getimagesize ($file); $source = $this->createimg ($file); Imagecopyresampled ($img, $source, 0, 0, 0, 0, $width, $height, $w, $h); $value = $this->gethashvalue ($img); Imagedestroy ($IMG); return $value; The Public Function Gethashvalue ($img) {$width = Imagesx ($img); $height = Imagesy ($img); $total= 0; $array = Array (); for ($y =0; $y < $height; $y + +) {for ($x =0; $x < $width; $x + +) {$gray = (Imagecolorat ($img, $x, $y) >> 8) & 0xF  F  if (!is_array ($array [$y])) {$array [$y] = array ();  } $array [$y] [$x] = $gray;  $total + = $gray; }} $average = Intval ($total/(* $this->rate * $this->rate)); $result = ";  for ($y =0; $y < $height; $y + +) {for ($x =0; $x < $width; $x + +) {if ($array [$y] [$x] >= $average) {$result. = ' 1 ';  }else{$result. = ' 0 '; }}} return $result; Public Function createimg ($file) {$ext = $this->getfileext ($file), if ($ext = = = ' jpeg ') $ext = ' jpg '; $img = null; SW  Itch ($ext) {case ' png ': $img = Imagecreatefrompng ($file);  Case ' jpg ': $img = Imagecreatefromjpeg ($file); Case ' gif ': $img = Imagecreatefromgif ($file); } return $img; The Public Function Getfileext ($file) {$infos = explode ('. ', $file); $ext = Strtolower ($infos [Count ($infos)-1]); return $e xt }}

The method is called as follows:

Require_once "Imghash.class.php"; $instance = Imghash::getinstance (); $result = $instance->checkissimilarimg (' Chenyin/img_3214.png ', ' chenyin/img_3212.jpg ');

If the $result value is true, it indicates that 2 pictures are similar, otherwise not similar.

http://www.bkjia.com/PHPjc/1057474.html www.bkjia.com true http://www.bkjia.com/PHPjc/1057474.html techarticle PHP Implementation search similar images, perceptual hashing algorithm count = 5 matches most similar count 102 different picture var_dump (Imagehash::run ('./1.png ', './psb.jpg ')); Phpclass Imageh Ash {...

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