PHP图像调整大小为不同的mime类型

时间:2012-09-10 05:03:14

标签: php image resize

我是一个php noob,并试图创建一个图像大小调整脚本,将上传的图像缩小到更小的尺寸。使用我当前的脚本,我会显示原始图像。新的宽度和高度似乎没有注册。任何帮助表示赞赏。

    <?php

    if ($_SERVER['REQUEST_METHOD']=='POST') {
      if (isset($_FILES['image']['tmp_name'])) {
        if ($_FILES['image']['error']==0){
        $new_dir = '/PHP_MySQL_Practice/uploaded/images';
        $fullpath = $_SERVER['DOCUMENT_ROOT'].$new_dir;
        if(!is_dir($fullpath)) {
            mkdir($fullpath, 0777, TRUE); 
        }
        //get file name and type(extension)
        $name = $_FILES['image']['name'];
        $type = $_FILES['image']['type'];

        //separate image name after first "dot"
        $separated = explode(".", $name);
        //get string before the dot which was stored as the 1st item in the separated array.
        $first = $separated[0];
        //use php function pathinfo to get extension of image file
        $ext = pathinfo($name, PATHINFO_EXTENSION);
        //concatenate current timestamp (to avoid file overwrites) with the extracted file 'firstname' and add the extension
        $name = time().'_'.$first.'.'.$ext;
        $target = $fullpath.'/'.$name;

        if (move_uploaded_file($_FILES['image']['tmp_name'], $target)) {

            resizeImage($target, $name);
            echo '<img src="' . $target . '"/>';

        }

    }
    else {

        echo 'there was an error in saving ur image file.';
    }
}   
else {

    echo 'ur image could not be uploaded.';
}
    }
    else {
    ?>
<form method="POST" enctype="multipart/form-data">
    <label>upload image: </label>
    <input type="file" name="image" />
    <input type="submit" />
</form> 
    <?php   
    }

    //function to resize image
    function resizeImage($dir, $img) {
list($src_w, $src_h) = getimagesize($dir);
$max_w = 150;
$max_h = 150;
if ($src_w > $max_w) {
    $ratio = $max_w / $src_w;
    $new_img_w = $src_w * $ratio;
}
else if ($src_h > $max_h) {
    $ratio = $max_h / $src_h;
    $new_img_h = $src_h * $ratio;
}
$img_mime_type = getimagesize($dir);
switch ($img_mime_type['mime']) {
    case 'image/jpeg':
    case 'image/pjpeg':
        $src = imagecreatefromjpeg($dir);
        return $src;
        break;
    case 'image/gif':
        $src = imagecreatefromgif($dir);
        return $src;
        break;
    case 'image/png':
        $src = imagecreatefrompng($dir);
        return $src;
        break;
    default:
        return FALSE;
        break;
}
$new_img = imagecreatetruecolor($new_img_w, $new_img_h);
imagecopyresampled($new_img, $src, 0, 0, 0, 0, $new_img_w, $new_img_h, $max_w, $max_h);
switch ($img_mime_type['mime']) {
    case 'image/jpeg':
    case 'image/pjpeg':
        imagejpeg($new_img, $dir, 100);
        break;
    case 'image/gif':
        imagegif($new_img, $dir);
        break;
    case 'image/png':
        imagepng($new_img, $dir);
        break;
    default:
        return FALSE;
        break;
}

imagedestroy($src);
imagedestroy($new_img);
    }
    ?>

4 个答案:

答案 0 :(得分:3)

那里有一些缺陷

  1. imagegif只有2个参数$im并保存位置
  2. imagepng的压缩级别为0到9而不是100
  3. 您未保存图片,null imagejpeg($new_img, null, 100);应更改为$dir
  4. 您的上一个功能imagdestroy($src);错误,应为imagedestroy($src);
  5. 您的switch应该是:

    switch ($img_mime_type['mime']) {
        case 'image/jpeg':
        case 'image/pjpeg':
            imagejpeg($new_img, $dir, 100);
            break;
        case 'image/gif':
            imagegif($new_img, $dir);
            break;
        case 'image/png':
            imagepng($new_img, $dir);
            break;
        default:
            return FALSE;
            break;
    }
    

    你的调整大小功能:

    function resizeImage($dir, $img) {
        //echo $dir; die;
        list($src_w, $src_h) = getimagesize($dir);
        $max_w = 150;
        $max_h = 150;
        if ($src_w > $max_w) {
            $ratio = $max_w / $src_w;
            $max_w = $src_w * $ratio;
        }
        else if ($src_h > $max_h) {
            $ratio = $max_h / $src_h;
            $max_h = $src_h * $ratio;
        }
        $img_mime_type = getimagesize($dir);
        $src = imagecreatefromstring(file_get_contents($dir));
        $new_img = imagecreatetruecolor($max_w, $max_h);
        imagecopyresampled($new_img, $src, 0, 0, 0, 0, $max_w, $max_h, $src_w, $src_h);
        switch ($img_mime_type['mime']) {
            case 'image/jpeg':
            case 'image/pjpeg':
                imagejpeg($new_img, $dir, 100);
                break;
            case 'image/gif':
                imagegif($new_img, $dir);
                break;
            case 'image/png':
                imagepng($new_img, $dir);
                break;
            default:
                return FALSE;
                break;
        }
    
        imagedestroy($src);
        imagedestroy($new_img);
    }
    

答案 1 :(得分:0)

您不是保存图像,而是输出图像的内容。如果查看imagejpeg的文档,您将看到第二个参数是您要保存图像的路径。因此,将第二个参数(null)更改为要保存已调整大小的图像的位置。

答案 2 :(得分:0)

使用以下功能调整图像大小

function image_resize($image, $maxWidth, $maxHeight = null)
{
        $file = $image;
        $file_headers = @get_headers($file);

        //validate file not exists
        if( isset($file_headers[0]) && strpos($file_headers[0], '404') ) {
            return;
        }

    $arrayUploadPath = wp_upload_dir();
    $fileUploadSubDir = str_replace(basename($image),'', str_replace($arrayUploadPath['baseurl'], '', $image));
    $fileUploadDir = $arrayUploadPath['basedir'] . $fileUploadSubDir;

    //validate sour ce file existance
    if(!file_exists($fileUploadDir . basename($src))) return null;

    $fileUploadUrl = $arrayUploadPath['baseurl'] . $fileUploadSubDir;
    $srcFileName = $fileUploadDir . basename($image);
    $srcSize = getimagesize($srcFileName);
    $width = $srcSize[0];
    $height = $srcSize[1];

    if( empty($maxHeight) ) {
        $size = wp_constrain_dimensions($width, $height, $maxWidth);
        $maxHeight = $size[1];
    }

    //fix for image_resize_dimensions() constraint in image_resize() function
    if($maxHeight >= $height) $maxHeight = $height - 1;

    $newImage = image_resize($srcFileName, $maxWidth, $maxHeight);

    $newFileNameUrl = !empty($newImage) && !is_object($newImage) ? $fileUploadUrl . basename($newImage) : null;

    return $newFileNameUrl;
}

答案 3 :(得分:0)

试试这个功能......

在此功能中,您可以根据需要传递高度和宽度,因为总共有三种可能性,您可以按比例调整图像大小

  1. 如果高度超过宽度,则必须调整高度。
  2. 如果宽度超过宽度,则必须使用宽度调整大小。
  3. 调整高度和宽度。
  4. 这是示例,

    //first of all get Height and width of image 
    
     function getHeight($image) {
        $sizes = getimagesize($image);
        $height = $sizes[1];
        return $height;
    }
    
    //You do not need to alter these functions
    function getWidth($image) {
        $sizes = getimagesize($image);
        $width = $sizes[0];
        return $width;
    }
    

    现在调整所需的尺寸,我正在使用500px(高度和宽度)

        $width = $this->getWidth($fullpath);
        $height = $this->getHeight($fullpath);
    
         $profilecroppedthumb = UPLOAD_PATH."FILENAME_WITH_EXTENSION";
         $fullpath = $uploadDirectory.$filename.'.'.$ext;
    
            if ($width >= 500 && $height >= 500) {
                thumb($fullpath, $profilecroppedthumb, "500", "500");
            }
            elseif($width >= 500 && $height <= 500)
            {
                thumb($fullpath, $profilecroppedthumb, "500", "");
            } 
            elseif($width <= 500 && $height >= 500)
            {
                thumb($fullpath, $profilecroppedthumb, "", "500");
            }
            else
            {
                $target = fopen($profilecroppedthumb, "w");
                fseek($temp, 0, SEEK_SET);
                stream_copy_to_stream($temp, $target);
                fclose($target);
            } 
     function thumb($file, $save, $width="", $height="")
    {   
        //GD-Lib > 2.0 only!
        //@unlink($save);
    
        //get sizes else stop
    
        if (!$infos = @getimagesize($file)) {
        //echo $infos = @getimagesize($file); exit('saf');
            return false;
        }
    
        // keep proportions
        $iWidth = $infos[0];
        $iHeight = $infos[1];
        $iRatioW = $width / $iWidth;
        $iRatioH = $height / $iHeight;
    
    
        if($height == "" ) {
            if ($iRatioW < $iRatioH) {
                    $iNewW = $iWidth * $iRatioW;
                    $iNewH = $iHeight * $iRatioW;
                } else {
                    $iNewW = $iWidth * $iRatioW;
                    $iNewH = $iHeight * $iRatioW;
                }
        }
        elseif ($width == "")
        {
        if ($iRatioW < $iRatioH) {
                    $iNewW = $iWidth * $iRatioH;
                    $iNewH = $iHeight * $iRatioH;
                } else {
                    $iNewW = $iWidth * $iRatioH;
                    $iNewH = $iHeight * $iRatioH;
                }
        }
        else 
        {
            if ($iRatioW < $iRatioH) {
                $iNewW = $iWidth * $iRatioW;
                $iNewH = $iHeight * $iRatioW;
            } else {
    
                $iNewW = $iWidth * $iRatioH;
                $iNewH = $iHeight * $iRatioH;
    
    
            }
        }
        //$iNewW = $width;
        //$iNewH = $height;
    
        //Don't resize images which are smaller than thumbs
        if ($infos[0] < $width && $infos[1] < $height) {
            $iNewW = $infos[0];
            $iNewH = $infos[1];
        }
    
        if($infos[2] == 1) {
            /*
            * Image is typ gif
            */
            $imgA = imagecreatefromgif($file);
            $imgB = imagecreate($iNewW,$iNewH);
    
            //keep gif transparent color if possible
            if(function_exists('imagecolorsforindex') && function_exists('imagecolortransparent')) {
                $transcolorindex = imagecolortransparent($imgA);
                    //transparent color exists
                    if($transcolorindex >= 0 ) {
                        $transcolor = imagecolorsforindex($imgA, $transcolorindex);
                        $transcolorindex = imagecolorallocate($imgB, $transcolor['red'], $transcolor['green'], $transcolor['blue']);
                        imagefill($imgB, 0, 0, $transcolorindex);
                        imagecolortransparent($imgB, $transcolorindex);
                    //fill white
                    } else {
                        $whitecolorindex = @imagecolorallocate($imgB, 255, 255, 255);
                        imagefill($imgB, 0, 0, $whitecolorindex);
                    }
            //fill white
            } else {
                $whitecolorindex = imagecolorallocate($imgB, 255, 255, 255);
                imagefill($imgB, 0, 0, $whitecolorindex);
            }
            imagecopyresampled($imgB, $imgA, 0, 0, 0, 0, $iNewW, $iNewH, $infos[0], $infos[1]);
            imagegif($imgB, $save);        
    
        } elseif($infos[2] == 2) {
            /*
            * Image is typ jpg
    
            */
            $imgA = imagecreatefromjpeg($file);
            $imgB = imagecreatetruecolor($iNewW,$iNewH);
            imagecopyresampled($imgB, $imgA, 0, 0, 0, 0, $iNewW, $iNewH, $infos[0], $infos[1]);
            imagejpeg($imgB, $save,100);
    
        } elseif($infos[2] == 3) {
            /*
            * Image is typ png
            */
            $imgA = imagecreatefrompng($file);
            $imgB = imagecreatetruecolor($iNewW, $iNewH);
            imagealphablending($imgB, false);
            imagecopyresampled($imgB, $imgA, 0, 0, 0, 0, $iNewW, $iNewH, $infos[0], $infos[1]);
            imagesavealpha($imgB, true);
            imagepng($imgB, $save,100);
        } else {
            return false;
        }
    
        return true;
    }
    

    希望这有帮助...