When building web applications in PHP, handling image uploads and resizing them is a common task. In this tutorial, we will demonstrate how to create a simple PHP script to upload and resize images. This guide covers creating a file upload form and processing the uploaded file to resize it.<\/p>\n\n\n\n
First, we need to create a form that allows users to upload their images. We will create two files: This file contains the HTML form for users to upload their images.<\/p>\n\n\n\n The When the form is submitted, the file data is sent to The Uploading and resizing images in PHP is a straightforward process. By following the steps outlined in this tutorial, you can easily implement this functionality in your own projects. This guide provides the core code needed to upload and resize images, ensuring your application can handle images effectively.<\/p>\n\n\n\nindex.php<\/strong><\/code> for the form and upload_file.php<\/strong><\/code> to handle the upload and resizing process.<\/p>\n\n\n\nindex.php<\/h2>\n\n\n\n
<!DOCTYPE html>\n<html>\n<head>\n <title>Upload and Resize Image<\/title>\n<\/head>\n<body>\n <form action=\"upload_file.php\" method=\"post\" enctype=\"multipart\/form-data\">\n <label for=\"file\">Filename:<\/label>\n <input type=\"file\" name=\"file\" id=\"file\"><br>\n <input type=\"submit\" name=\"submit\" value=\"Submit\">\n <\/form>\n<\/body>\n<\/html>\n<\/code><\/pre>\n\n\n\nenctype=\"multipart\/form-data\"<\/code><\/strong> attribute is crucial for file uploads via POST. Without this, the file upload will not work.<\/p>\n\n\n\nHandling the File Upload and Resizing<\/h2>\n\n\n\n
upload_file.php<\/code> for processing. This file will handle the upload and resizing logic.<\/p>\n\n\n\nupload_file.php<\/h2>\n\n\n\n
<?php\nif ($_FILES) {\n $allowedExts = array(\"gif\", \"jpeg\", \"jpg\", \"png\");\n $temp = explode(\".\", $_FILES[\"file\"][\"name\"]);\n $extension = end($temp);\n\n if ((($_FILES[\"file\"][\"type\"] == \"image\/gif\")\n || ($_FILES[\"file\"][\"type\"] == \"image\/jpeg\")\n || ($_FILES[\"file\"][\"type\"] == \"image\/jpg\")\n || ($_FILES[\"file\"][\"type\"] == \"image\/pjpeg\")\n || ($_FILES[\"file\"][\"type\"] == \"image\/x-png\")\n || ($_FILES[\"file\"][\"type\"] == \"image\/png\"))\n && ($_FILES[\"file\"][\"size\"] < 2000000)\n && in_array($extension, $allowedExts)) {\n\n if ($_FILES[\"file\"][\"error\"] > 0) {\n echo \"Return Code: \" . $_FILES[\"file\"][\"error\"] . \"<br>\";\n } else {\n $filename = \"upload\/\" . $_FILES[\"file\"][\"name\"];\n move_uploaded_file($_FILES[\"file\"][\"tmp_name\"], $filename);\n \n $resized_filename = \"upload\/\" . 'thumb-'.$_FILES[\"file\"][\"name\"];\n resize_image($filename, $resized_filename, 150, 150);\n\n echo \"Stored in: \" . $filename;\n }\n } else {\n echo \"Invalid file\";\n }\n}\n\nfunction resize_image($file, $destination, $w, $h) {\n list($source_width, $source_height, $source_type) = getimagesize($file);\n $ext = strtolower(pathinfo($file, PATHINFO_EXTENSION));\n\n switch ($ext) {\n case 'jpg':\n case 'jpeg':\n $source_gdim = imagecreatefromjpeg($file);\n break;\n case 'png':\n $source_gdim = imagecreatefrompng($file);\n break;\n case 'gif':\n $source_gdim = imagecreatefromgif($file);\n break;\n default:\n return;\n }\n\n $source_aspect_ratio = $source_width \/ $source_height;\n $desired_aspect_ratio = $w \/ $h;\n\n if ($source_aspect_ratio > $desired_aspect_ratio) {\n $temp_height = $h;\n $temp_width = (int)($h * $source_aspect_ratio);\n } else {\n $temp_width = $w;\n $temp_height = (int)($w \/ $source_aspect_ratio);\n }\n\n $temp_gdim = imagecreatetruecolor($temp_width, $temp_height);\n imagecopyresampled($temp_gdim, $source_gdim, 0, 0, 0, 0, $temp_width, $temp_height, $source_width, $source_height);\n\n $x0 = ($temp_width - $w) \/ 2;\n $y0 = ($temp_height - $h) \/ 2;\n $desired_gdim = imagecreatetruecolor($w, $h);\n imagecopy($desired_gdim, $temp_gdim, 0, 0, $x0, $y0, $w, $h);\n\n switch ($ext) {\n case 'jpg':\n case 'jpeg':\n imagejpeg($desired_gdim, $destination, 100);\n break;\n case 'png':\n imagepng($desired_gdim, $destination);\n break;\n case 'gif':\n imagegif($desired_gdim, $destination);\n break;\n }\n\n imagedestroy($desired_gdim);\n}\n?>\n<\/code><\/pre>\n\n\n\nExplanation<\/h3>\n\n\n\n
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move_uploaded_file<\/code> function uploads the image to the upload<\/code> directory.<\/li>\n\n\n\nresize_image<\/code> function resizes the uploaded image to the specified dimensions and saves it with a new name.<\/li>\n<\/ul>\n\n\n\nDetailed Resizing Function<\/h3>\n\n\n\n
resize_image<\/code> function is responsible for resizing the uploaded image. It supports JPEG, PNG, and GIF formats. Here’s a breakdown of the function:<\/p>\n\n\n\n\n
getimagesize<\/code> function retrieves the width, height, and type of the image.<\/li>\n\n\n\nimagecreatefromjpeg<\/code>, imagecreatefrompng<\/code>, or imagecreatefromgif<\/code>.<\/li>\n\n\n\nimagecopyresampled<\/code> function creates a new true color image with the specified dimensions.<\/li>\n\n\n\nimagejpeg<\/code>, imagepng<\/code>, or imagegif<\/code>.<\/li>\n<\/ul>\n\n\n\nConclusion<\/h2>\n\n\n\n