Resize image on upload question

[skter4938]

Hello there,

 

Well basically I have a script that uploads an image and creates a sized thumbnail from it. I can't figure out how I can also resize the image if it is too big.

 

Say I have an image that is 400x856 px, well since the width is bigger than my wanted 750px, I would like the image to resize dinamically keeping the same ratio.

 

Here is my code for the upload, if someone could help me out that would be great.

 

<?php
//define a maxim size for the uploaded images
define ("MAX_SIZE","5000"); 
// define the width and height for the thumbnail
// note that theese dimmensions are considered the maximum dimmension and are not fixed, 
// because we have to keep the image ratio intact or it will be deformed
define ("WIDTH","75"); 
define ("HEIGHT","25"); 

  // this is the function that will create the thumbnail image from the uploaded image
// the resize will be done considering the width and height defined, but without deforming the image
function make_thumb($img_name,$filename,$new_w,$new_h)
{
	//get image extension.
	$ext=getExtension($img_name);
	//creates the new image using the appropriate function from gd library
	if(!strcmp("jpg",$ext) || !strcmp("jpeg",$ext))
		$src_img=imagecreatefromjpeg($img_name);

  	if(!strcmp("png",$ext))
		$src_img=imagecreatefrompng($img_name);

if(!strcmp("gif",$ext))
	$src_img=imagecreatefrompng($img_name);

	 	//gets the dimmensions of the image
	$old_x=imageSX($src_img);
	$old_y=imageSY($src_img);

	 // next we will calculate the new dimmensions for the thumbnail image
	// the next steps will be taken: 
	// 	1. calculate the ratio by dividing the old dimmensions with the new ones
	//	2. if the ratio for the width is higher, the width will remain the one define in WIDTH variable
	//		and the height will be calculated so the image ratio will not change
	//	3. otherwise we will use the height ratio for the image
	// as a result, only one of the dimmensions will be from the fixed ones
	$ratio1=$old_x/$new_w;
	$ratio2=$old_y/$new_h;
	if($ratio1>$ratio2)	{
		$thumb_w=$new_w;
		$thumb_h=$old_y/$ratio1;
	}
	else	{
		$thumb_h=$new_h;
		$thumb_w=$old_x/$ratio2;
	}

  	// we create a new image with the new dimmensions
	$dst_img=ImageCreateTrueColor($thumb_w,$thumb_h);

	// resize the big image to the new created one
	imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y); 

	// output the created image to the file. Now we will have the thumbnail into the file named by $filename
	if(!strcmp("png",$ext))
		imagepng($dst_img,$filename); 
	else
		imagejpeg($dst_img,$filename); 

  	//destroys source and destination images. 
	imagedestroy($dst_img); 
	imagedestroy($src_img); 
}

// This function reads the extension of the file. 
// It is used to determine if the file is an image by checking the extension. 
function getExtension($str) {
         $i = strrpos($str,".");
         if (!$i) { return ""; }
         $l = strlen($str) - $i;
         $ext = substr($str,$i+1,$l);
         return $ext;
}
// This variable is used as a flag. The value is initialized with 0 (meaning no error found) 
//and it will be changed to 1 if an errro occures. If the error occures the file will not be uploaded.
$errors=0;
// checks if the form has been submitted
if(isset($_POST['Submit']))
{
//reads the name of the file the user submitted for uploading
	$image=$_FILES['image']['name'];
	// if it is not empty
	if ($image) 
	{
		// get the original name of the file from the clients machine
		$filename = stripslashes($_FILES['image']['name']);

		// get the extension of the file in a lower case format
	 	$extension = getExtension($filename);
		$extension = strtolower($extension);
		// if it is not a known extension, we will suppose it is an error, print an error message 
		//and will not upload the file, otherwise we continue
		if (($extension != "jpg")  && ($extension != "jpeg") && ($extension != "png"))
		{
			echo 'Unknown extension!<br>';
			$errors=1;
		}
		else
		{
			// get the size of the image in bytes
			// $_FILES[\'image\'][\'tmp_name\'] is the temporary filename of the file in which 
		//the uploaded file was stored on the server
			$size=getimagesize($_FILES['image']['tmp_name']);
			$sizekb=filesize($_FILES['image']['tmp_name']);

			//compare the size with the maxim size we defined and print error if bigger
			if ($sizekb > MAX_SIZE*1024)
			{
				echo 'The file you are uploading is far too large<br>';
				$errors=1;
			}

  			//we will give an unique name, for example the time in unix time format
			$image_name=time().'.'.$extension;
			//the new name will be containing the full path where will be stored (images folder)
		 	$newname="gd/imgupload/images/".$image_name;
			$copied = copy($_FILES['image']['tmp_name'], $newname);
			//we verify if the image has been uploaded, and print error instead
			if (!$copied) 
			{
				echo 'Copy unsuccessfull!<br>';
				$errors=1;
			}
			else
			{
				// the new thumbnail image will be placed in images/thumbs/ folder
				$thumb_name='gd/imgupload/images/thumbs/'.$image_name;
				// call the function that will create the thumbnail. The function will get as parameters 
				//the image name, the thumbnail name and the width and height desired for the thumbnail
				$thumb=make_thumb($newname,$thumb_name,WIDTH,HEIGHT);
			}}	}}

  //If no errors registred, print the success message and show the thumbnail image created
if(isset($_POST['Submit']) && !$errors) 
{
	echo "Upload successfull.<br>";
	echo '<img src="'.$thumb_name.'">';
}

  ?>

[skter4938]

Anyone? I kind of need this asap.

[teng84]

i dont know how to resize them permanently but if what you are saying is to display them you can use the width and height of " <img src height='' width=''>

[skter4938]

Well no, basically what I want it for the admin to upload a picture. Then if the picture is bigger than 750px in width, for it to resize it accordingly, and save it. Then create a thumbnail from it.

 

Basically my code does everything except resizing the original image.

[teng84]

http://www.php.net/manual/hu/function.imagecopyresized.php