用PHP调整图像大小 [英] Image resize with php

问题描述

function resize($originalImage){

          list($width, $height) = getimagesize($originalImage);
          $newName=basename($originalImage);
          $imageResized = imagecreatetruecolor(128, 128);
          $imageTmp     = imagecreatefromjpeg ($originalImage);
          imagecopyresampled($imageResized, $imageTmp, 0, 0, 0, 0, 128, 128, $width, $height);

          imagejpeg($imageResized, "resizedImg/$newName",100);
          imageDestroy($imageResized);

}

脚本返回具有正确名称的图像，但是它只是黑色的吗?有任何想法吗?

The script returns the image with the correct name but it's just black? Any ideas?

推荐答案

如果无法调整图像大小，请使用此代码.根据需要进行修改.

If you have trouble with image resizing use this code for it. Do the modifications as you need it.

function resizeImage($file){

         define ('MAX_WIDTH', 1500);//max image width               
         define ('MAX_HEIGHT', 1500);//max image height 
         define ('MAX_FILE_SIZE', 10485760);

         //iamge save path
         $path = 'storeResize/';  

        //size of the resize image 
         $new_width = 128; 
         $new_height = 128;    

        //name of the new image           
        $nameOfFile = 'resize_'.$new_width.'x'.$new_height.'_'.basename($file['name']);       

        $image_type = $file['type'];
        $image_size = $file['size'];
        $image_error = $file['error'];
        $image_file = $file['tmp_name'];
        $image_name = $file['name'];        

        $image_info = getimagesize($image_file);

        //check image type 
        if ($image_info['mime'] == 'image/jpeg' or $image_info['mime'] == 'image/jpg'){    
        }
        else if ($image_info['mime'] == 'image/png'){    
        }
        else if ($image_info['mime'] == 'image/gif'){    
        }
        else{            
            //set error invalid file type
        }

        if ($image_error){
            //set error image upload error
        }

        if ( $image_size > MAX_FILE_SIZE ){
            //set error image size invalid
        }

        switch ($image_info['mime']) {
            case 'image/jpg': //This isn't a valid mime type so we should probably remove it
            case 'image/jpeg':
            $image = imagecreatefromjpeg ($image_file);
            break;
            case 'image/png':
            $image = imagecreatefrompng ($image_file);
            break;
            case 'image/gif':
            $image = imagecreatefromgif ($image_file);
            break;
        }    

        if ($new_width == 0 && $new_height == 0) {
            $new_width = 100;
            $new_height = 100;
        }

        // ensure size limits can not be abused
        $new_width = min ($new_width, MAX_WIDTH);
        $new_height = min ($new_height, MAX_HEIGHT);

        //get original image h/w
        $width = imagesx ($image);
        $height = imagesy ($image);

        //$align = 'b';
        $zoom_crop = 1;
        $origin_x = 0;
        $origin_y = 0;
        //TODO setting Memory

        // generate new w/h if not provided
        if ($new_width && !$new_height) {
            $new_height = floor ($height * ($new_width / $width));
        } else if ($new_height && !$new_width) {
            $new_width = floor ($width * ($new_height / $height));
        }

        // scale down and add borders
    if ($zoom_crop == 3) {

         $final_height = $height * ($new_width / $width);

         if ($final_height > $new_height) {
            $new_width = $width * ($new_height / $height);
         } else {
            $new_height = $final_height;
         }

    }

        // create a new true color image
        $canvas = imagecreatetruecolor ($new_width, $new_height);
        imagealphablending ($canvas, false);


        if (strlen ($canvas_color) < 6) {
            $canvas_color = 'ffffff';       
        }

        $canvas_color_R = hexdec (substr ($canvas_color, 0, 2));
        $canvas_color_G = hexdec (substr ($canvas_color, 2, 2));
        $canvas_color_B = hexdec (substr ($canvas_color, 2, 2));

        // Create a new transparent color for image
        $color = imagecolorallocatealpha ($canvas, $canvas_color_R, $canvas_color_G, $canvas_color_B, 127);

        // Completely fill the background of the new image with allocated color.
        imagefill ($canvas, 0, 0, $color);

        // scale down and add borders
    if ($zoom_crop == 2) {

            $final_height = $height * ($new_width / $width);

        if ($final_height > $new_height) {
            $origin_x = $new_width / 2;
            $new_width = $width * ($new_height / $height);
            $origin_x = round ($origin_x - ($new_width / 2));
            } else {

            $origin_y = $new_height / 2;
            $new_height = $final_height;
            $origin_y = round ($origin_y - ($new_height / 2));

        }

    }

        // Restore transparency blending
        imagesavealpha ($canvas, true);

        if ($zoom_crop > 0) {

            $src_x = $src_y = 0;
            $src_w = $width;
            $src_h = $height;

            $cmp_x = $width / $new_width;
            $cmp_y = $height / $new_height;

            // calculate x or y coordinate and width or height of source
            if ($cmp_x > $cmp_y) {
        $src_w = round ($width / $cmp_x * $cmp_y);
        $src_x = round (($width - ($width / $cmp_x * $cmp_y)) / 2);
            } else if ($cmp_y > $cmp_x) {
        $src_h = round ($height / $cmp_y * $cmp_x);
        $src_y = round (($height - ($height / $cmp_y * $cmp_x)) / 2);
            }

            // positional cropping!
        if ($align) {
            if (strpos ($align, 't') !== false) {
                $src_y = 0;
            }
                        if (strpos ($align, 'b') !== false) {
                                $src_y = $height - $src_h;
                        }
                        if (strpos ($align, 'l') !== false) {
                $src_x = 0;
            }
            if (strpos ($align, 'r') !== false) {
                $src_x = $width - $src_w;
            }
        }

            // positional cropping!
            imagecopyresampled ($canvas, $image, $origin_x, $origin_y, $src_x, $src_y, $new_width, $new_height, $src_w, $src_h);

         } else {       
        imagecopyresampled ($canvas, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
    }
        //Straight from Wordpress core code. Reduces filesize by up to 70% for PNG's
        if ( (IMAGETYPE_PNG == $image_info[2] || IMAGETYPE_GIF == $image_info[2]) && function_exists('imageistruecolor') && !imageistruecolor( $image ) && imagecolortransparent( $image ) > 0 ){
            imagetruecolortopalette( $canvas, false, imagecolorstotal( $image ) );
    }
        $quality = 100;            
        $nameOfFile = 'resize_'.$new_width.'x'.$new_height.'_'.basename($file['name']);       

    if (preg_match('/^image\/(?:jpg|jpeg)$/i', $image_info['mime'])){                       
        imagejpeg($canvas, $path.$nameOfFile, $quality);  

    } else if (preg_match('/^image\/png$/i', $image_info['mime'])){                         
        imagepng($canvas, $path.$nameOfFile, floor($quality * 0.09)); 

    } else if (preg_match('/^image\/gif$/i', $image_info['mime'])){               
        imagegif($canvas, $path.$nameOfFile); 

    }
}

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