[PHP] 画像からシンメトリー画像を作成

symmetrizer.php

<?php
/*
【シンメトリー画像作成】

$_GET['d']が
L・・・左側を切り取り右に反転
R・・・右側を切り取り左に反転
T・・・上側を切り取り下に反転
B・・・下側を切り取り上に反転

例）http://example.com/symmetrizer.php?d=L

※重くなるが「LB」や「LBTR」と重ねがけも可能。(3つ以上は意味がないけど…)
※なんらかの失敗があると1x1pxの画像を出力。
*/

$filename='sample.jpg';
$filepath='/path/to/file/'.$filename;

$direction=!empty($_GET['d']) ? strtoupper($_GET['d']) : 'L';
if(!preg_match('/^[LRTB]+$/',$direction)){
	$direction='L';
}

$ext=substr($filename,strrpos($filename,'.')+1);

if($ext=='jpg' || $ext=='jpeg'){
	$src=imagecreatefromjpeg($filepath);
}else if($ext=='gif'){
	$src=imagecreatefromgif($filepath);
}else if($ext=='png'){
	$src=imagecreatefrompng($filepath);
}else{
	_exit($ext);
}

for($i=0;$i<strlen($direction);$i++){
	$src=symmetry($src,$direction{$i});
}

if($ext=='jpg' || $ext=='jpeg'){
	header("Content-type: image/jpeg");
	imagejpeg($src);
}else if($ext=='gif'){
	header("Content-type: image/gif");
	imagegif($src);
}else if($ext=='png'){
	header("Content-type: image/png");
	imagepng($src);
}else{
	_exit($ext);
}

exit;



###### functions ######

function symmetry($src,$direction='L'){
	if($direction!=='L' && $direction!=='R' && $direction!=='T' && $direction!=='B'){
		return false;
	}
	
	$srcX=imagesx($src);
	$srcY=imagesy($src);
	
	if($direction==='L' || $direction==='R'){
		$halfX=ceil($srcX/2);
		$half=imagecreatetruecolor($halfX,$srcY);
		if($direction==='L'){
			imagecopyresampled($half,$src,0,0,0,0,$srcX,$srcY,$srcX,$srcY);
			$halfL=$half;
			$halfR=flip_horizontal($half);
		}else{
			imagecopyresampled($half,$src,0,0,$halfX,0,$srcX,$srcY,$srcX,$srcY);
			$halfL=flip_horizontal($half);
			$halfR=$half;
		}
		
		if(empty($halfL) || empty($halfR)){
			_exit();
		}
		
		$temp=imagecreatetruecolor($srcX,$srcY);
		imagecopyresampled($temp,$halfL,0,0,0,0,$srcX,$srcY,$srcX,$srcY);
		imagecopyresampled($temp,$halfR,$halfX,0,0,0,$srcX,$srcY,$srcX,$srcY);
		
		return $temp;
	}else{
		$halfY=ceil($srcY/2);
		$half=imagecreatetruecolor($srcX,$halfY);
		if($direction==='T'){
			imagecopyresampled($half,$src,0,0,0,0,$srcX,$srcY,$srcX,$srcY);
			$halfT=$half;
			$halfB=flip_vertical($half);
		}else{
			imagecopyresampled($half,$src,0,0,0,$halfY,$srcX,$srcY,$srcX,$srcY);
			$halfT=flip_vertical($half);
			$halfB=$half;
		}
		
		if(empty($halfT) || empty($halfB)){
			_exit();
		}
		
		$temp=imagecreatetruecolor($srcX,$srcY);
		imagecopyresampled($temp,$halfT,0,0,0,0,$srcX,$srcY,$srcX,$srcY);
		imagecopyresampled($temp,$halfB,0,$halfY,0,0,$srcX,$srcY,$srcX,$srcY);
		
		return $temp;
	}
}

function flip_vertical($imgsrc){
	$x=imagesx($imgsrc);
	$y=imagesy($imgsrc);
	$flip=imagecreatetruecolor($x,$y);
	if(imagecopyresampled($flip,$imgsrc,0,0,0,$y-1,$x,$y,$x,0-$y)){
		return $flip;
	}else{
		return $imgsrc;
	}
}

function flip_horizontal($imgsrc){
	$x=imagesx($imgsrc);
	$y=imagesy($imgsrc);
	$flip=imagecreatetruecolor($x,$y);
	if(imagecopyresampled($flip,$imgsrc,0,0,$x-1,0,$x,$y,0-$x,$y)){
		return $flip;
	}else{
		return $imgsrc;
	}
}

function _exit($ext='jpg'){
	if($ext=='png'){
		header("Content-type: image/png");
		$src=base64_decode('iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA3NCSVQICAjb4U/gAAAABlBMVEX///////9VfPVsAAAAAnRSTlMA/1uRIrUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAWdEVYdENyZWF0aW9uIFRpbWUAMDgvMzEvMTDLNYXzAAAAH3RFWHRTb2Z0d2FyZQBNYWNyb21lZGlhIEZpcmV3b3JrcyA4tWjSeAAAAApJREFUCJljYAAAAAIAAfRxZKYAAAAASUVORK5CYII=');
		$src=imagecreatefromstring($src);
		imagepng($src);
	}else if($ext=='gif'){
		header("Content-type: image/gif");
		$src=base64_decode('R0lGODlhAQABAIAAAP///////yH5BAEHAAAALAAAAAABAAEAAAICRAEAOw==');
		$src=imagecreatefromstring($src);
		imagegif($src);
	}else{
		header("Content-type: image/jpeg");
		$src=base64_decode('/9j/4AAQSkZJRgABAQEAYABgAAD/2wBDAAYEBAQFBAYFBQYJBgUGCQsIBgYICwwKCgsKCgwQDAwMDAwMEAwODxAPDgwTExQUExMcGxsbHCAgICAgICAgICD/2wBDAQcHBw0MDRgQEBgaFREVGiAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICD/wAARCAABAAEDAREAAhEBAxEB/8QAFAABAAAAAAAAAAAAAAAAAAAACP/EABQQAQAAAAAAAAAAAAAAAAAAAAD/xAAUAQEAAAAAAAAAAAAAAAAAAAAA/8QAFBEBAAAAAAAAAAAAAAAAAAAAAP/aAAwDAQACEQMRAD8AVIP/2Q==');
		$src=imagecreatefromstring($src);
		imagejpeg($src);
	}
	exit;
}
?>