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類似画像 jpg,png,gif対応
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http://yuzurus.hatenablog.jp/entry/search-image | |
http://www.kochi-tech.ac.jp/library/ron/2012/2012info/1130340.pdf | |
http://aidiary.hatenablog.com/entry/20091003/1254574041 |
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<?php | |
// 画像ディレクトリパス | |
$dir = './images'; | |
// baseになる画像(画像URLでも可) | |
$base_image_path = './images/sample.jpeg'; | |
// 比較する画像パスの配列 | |
$image_paths = glob($dir . '/{*.jpeg,*.jpg,*.png,*.gif}', GLOB_BRACE); | |
// base画像のヒストグラム | |
$base_his = makeHistogram($base_image_path); | |
// 比較画像のヒストグラム | |
$image_his = []; | |
foreach ($image_paths as $id => $path) { | |
$image_his[$id] = makeHistogram($path); | |
} | |
// 比較 | |
$result = []; | |
foreach ($image_his as $id => $his) { | |
for ($i = 0; $i < 64; $i++) { | |
$result[$id] += min($base_his[$i], $his[$i]); | |
} | |
} | |
print_r($result); | |
/** | |
* ヒストグラムのビンを計算 | |
* @param $rgb | |
* @return int | |
*/ | |
function rgb2no($colors) | |
{ | |
// gifがビットシフトで対応できないのでimagecolorsforindexでrgbを渡す | |
// $r = ($rgb >> 16) & 0xFF; | |
// $g = ($rgb >> 8) & 0xFF; | |
// $b = $rgb & 0xFF; | |
$r = $colors['red']; | |
$g = $colors['green']; | |
$b = $colors['blue']; | |
$rn = floor($r / 64); | |
$gn = floor($g / 64); | |
$bn = floor($b / 64); | |
return 16 * $rn + 4 * $gn + $bn; | |
} | |
/** | |
* 画像からカラーヒストグラムを作成(csv形式) | |
* @param $path 画像保存先 | |
* @param bool $cache | |
* @return array | |
*/ | |
function makeHistogram($path, $cache = true) | |
{ | |
/* | |
量が多い場合は毎度ファイルを作るわけにいかないので、結果をjson_encodeしてDBに保存 | |
*/ | |
$csvfile = preg_replace('/\.(jpg|jpeg)$/', '-his.csv', $path); | |
if ($cache) { | |
if (file_exists($csvfile)) { | |
$s = file_get_contents($csvfile); | |
return explode(',', $s); | |
} | |
} | |
if (strpos($path, '.png') !== false) { | |
$im = imagecreatefrompng($path); | |
} elseif (strpos($path, '.gif') !== false) { | |
$im = imagecreatefromgif($path); | |
} else { | |
$im = imagecreatefromjpeg($path); | |
} | |
$sx = imagesx($im); | |
$sy = imagesy($im); | |
// ピクセルを数える | |
$his = array_fill(0, 64, 0); | |
for ($y = 0; $y < $sy; $y++) { | |
for ($x = 0; $x < $sx; $x++) { | |
$rgb = imagecolorat($im, $x, $y); | |
$colors = imagecolorsforindex($im, $rgb); | |
$no = rgb2no($colors); | |
$his[$no]++; | |
} | |
} | |
// 8bitに正規化 | |
$pixels = $sx * $sy; | |
for ($i = 0; $i < 64; $i++) { | |
$his[$i] = floor(256 * $his[$i] / $pixels); | |
} | |
file_put_contents($csvfile, implode(',', $his)); | |
imagecolorsforindex($im); | |
return $his; | |
} |
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