PHP scales the png Image (supports transparent background) and png.

PHP scales the png Image (supports transparent background) and png.

This article describes how to scale png images using PHP. Share it with you for your reference. The specific implementation method is as follows:

function smart_resize_image( $file, $width = 0, $height = 0, $proportional = false, $output = 'file', $delete_original = true, $use_linux_commands = false ){    if ( $height <= 0 && $width <= 0 ) {      return false;    }    $info = getimagesize($file);    $image = '';    $final_width = 0;    $final_height = 0;    list($width_old, $height_old) = $info;    if ($proportional) {      if ($width == 0) $factor = $height/$height_old;      elseif ($height == 0) $factor = $width/$width_old;      else $factor = min ( $width / $width_old, $height / $height_old);       $final_width = round ($width_old * $factor);      $final_height = round ($height_old * $factor);    }    else {          $final_width = ( $width <= 0 ) ? $width_old : $width;      $final_height = ( $height <= 0 ) ? $height_old : $height;    }    switch ($info[2] ) {      case IMAGETYPE_GIF:        $image = imagecreatefromgif($file);      break;      case IMAGETYPE_JPEG:        $image = imagecreatefromjpeg($file);      break;      case IMAGETYPE_PNG:        $image = imagecreatefrompng($file);      break;      default:        return false;    }    $image_resized = imagecreatetruecolor( $final_width, $final_height );    if ( ($info[2] == IMAGETYPE_GIF) || ($info[2] == IMAGETYPE_PNG) ) {      $trnprt_indx = imagecolortransparent($image);      // If we have a specific transparent color      if ($trnprt_indx >= 0) {        // Get the original image's transparent color's RGB values        $trnprt_color  = imagecolorsforindex($image, $trnprt_indx);        // Allocate the same color in the new image resource        $trnprt_indx  = imagecolorallocate($image_resized, $trnprt_color['red'], $trnprt_color['green'], $trnprt_color['blue']);        // Completely fill the background of the new image with allocated color.        imagefill($image_resized, 0, 0, $trnprt_indx);        // Set the background color for new image to transparent        imagecolortransparent($image_resized, $trnprt_indx);      }      // Always make a transparent background color for PNGs that don't have one allocated already      elseif ($info[2] == IMAGETYPE_PNG) {        // Turn off transparency blending (temporarily)        imagealphablending($image_resized, false);        // Create a new transparent color for image        $color = imagecolorallocatealpha($image_resized, 0, 0, 0, 127);        // Completely fill the background of the new image with allocated color.        imagefill($image_resized, 0, 0, $color);        // Restore transparency blending        imagesavealpha($image_resized, true);      }    }    imagecopyresampled($image_resized, $image, 0, 0, 0, 0, $final_width, $final_height, $width_old, $height_old);    if ( $delete_original ) {      if ( $use_linux_commands )        exec('rm '.$file);      else        @unlink($file);    }    switch ( strtolower($output) ) {      case 'browser':        $mime = image_type_to_mime_type($info[2]);        header("Content-type: $mime");        $output = NULL;      break;      case 'file':        $output = $file;      break;      case 'return':        return $image_resized;      break;      default:      break;    }    switch ($info[2] ) {      case IMAGETYPE_GIF:        imagegif($image_resized, $output);      break;      case IMAGETYPE_JPEG:        imagejpeg($image_resized, $output);      break;      case IMAGETYPE_PNG:        imagepng($image_resized, $output);      break;      default:        return false;    }    return true;}

I hope this article will help you with php programming.