PHP實(shí)現(xiàn)圖片裁剪及縮放函數(shù)

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    PHP實(shí)現(xiàn)圖片裁剪及縮放函數(shù),根據(jù)自定義的目標(biāo)圖高寬, 按目標(biāo)圖高寬比裁剪、縮放源圖.
    傳入?yún)?shù):
    $source_path string 源圖路徑
    $target_width integer 目標(biāo)圖寬度
    $target_height integer 目標(biāo)圖高度
    源圖支持MIMETYPE: image/gif, image/jpeg, image/png。具體代碼如下:
    function imagecropper($source_path, $target_width, $target_height)
    {
    $source_info = getimagesize($source_path);
    $source_width = $source_info[0];
    $source_height = $source_info[1];
    $source_mime = $source_info['mime'];
    $source_ratio = $source_height / $source_width;
    $target_ratio = $target_height / $target_width;
    // 源圖過高
    if ($source_ratio > $target_ratio)
    {
    $cropped_width = $source_width;
    $cropped_height = $source_width * $target_ratio;
    $source_x = 0;
    $source_y = ($source_height - $cropped_height) / 2;
    }
    // 源圖過寬
    elseif ($source_ratio < $target_ratio)
    {
    $cropped_width = $source_height / $target_ratio;
    $cropped_height = $source_height;
    $source_x = ($source_width - $cropped_width) / 2;
    $source_y = 0;
    }
    // 源圖適中
    else
    {
    $cropped_width = $source_width;
    $cropped_height = $source_height;
    $source_x = 0;
    $source_y = 0;
    }
    switch ($source_mime)
    {
    case 'image/gif':
    $source_image = imagecreatefromgif($source_path);
    break;
    case 'image/jpeg':
    $source_image = imagecreatefromjpeg($source_path);
    break;
    case 'image/png':
    $source_image = imagecreatefrompng($source_path);
    break;
    default:
    return false;
    break;
    }
    $target_image = imagecreatetruecolor($target_width, $target_height);
    $cropped_image = imagecreatetruecolor($cropped_width, $cropped_height);
    // 裁剪
    imagecopy($cropped_image, $source_image, 0, 0, $source_x, $source_y, $cropped_width, $cropped_height);
    // 縮放
    imagecopyresampled($target_image, $cropped_image, 0, 0, 0, 0, $target_width, $target_height, $cropped_width, $cropped_height);
    header('Content-Type: image/jpeg');
    imagejpeg($target_image);
    imagedestroy($source_image);
    imagedestroy($target_image);
    imagedestroy($cropped_image);
    }