Resizing an image off a database

[cooldude832]

I have images stored in a mysql table as binary and i reproduce them with this script:

<?php
require_once("functions.php");
    // just so we know it is broken
    error_reporting(E_ALL);
    // some basic sanity checks
    if(isset($_GET['image_id']) && is_numeric($_GET['image_id'])) {
        //connect to the db
	connectSQL();
        // get the image from the db
        $sql = "SELECT image FROM Images WHERE ImageID=".$_GET['image_id'];
         // the result of the query
        $result = mysql_query("$sql") or die("Invalid query: " . mysql_error());
         // set the header for the image
        header("Content-type: image/jpeg");
        echo mysql_result($result, 0);
         // close the db link
        mysql_close($link);
    }
    else {
        echo 'Please use a real id number';
    }
?>

 

My question is how can i resize that (i.e make it the image resource for GD) thats my own issue is figuring out how to link it as a resource in gd if its a temp image.

[keeB]

Here's the code I use to resize an image by scale:

 

<?php
    public function ResizeByScale($scale, $outputFile) {
                /**
                 * @param float scale: The scale at which you want to resize the image
                 * @return: void
                 * 
                 * @output: Writes $outputFile to folder.
                 * 
                 */   

                $width     = $this->getWidth();
                $height    = $this->getHeight();
                $newWidth  = $width * $scale;
                $newHeight = $height * $scale;
        $image_p   = ImageCreateTrueColor($newWidth, $newHeight);
        $image     = ImageCreateFromJPEG($this->getPath());

        ImageCopyResampled($image_p, $image, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
        imagePNG($image_p, $outputFile, $this->getImageQuality());
?>

 

The thing you'll obviously have to modify is $width, $height, and the ImageCreateFromJPEG($this->getPath) <--- you can use your binary data for this I believe.

[cooldude832]

yeah i understand that  but can I use the binary as my image resource?

[keeB]

Yeah I am pretty sure you can.

[Barand]

I've never used this, as I don't use blob images, but maybe

 

imagecreatefromstring()

[cooldude832]

I'll look into it, but if i create the iamge first what would I use for my handler/how would i do that

[cooldude832]

I found this on php.net and i think it will suite my needs just fine

<?php
    $data = @mysql_result($result,0,"image");
    $type = @mysql_result($result,0,"filetype");
   
    Header( "Content-type: $type");   
   
    $size = 150;  // new image width
    $src = imagecreatefromstring($data);
    $width = imagesx($src);
    $height = imagesy($src);
    $aspect_ratio = $height/$width;

    if ($width <= $size) {
      $new_w = $width;
      $new_h = $height;
    } else {
      $new_w = $size;
      $new_h = abs($new_w * $aspect_ratio);
    }

    $img = imagecreatetruecolor($new_w,$new_h);
    imagecopyresized($img,$src,0,0,0,0,$new_w,$new_h,$width,$height);

    // determine image type and send it to the client   
    if ($type == "image/pjpeg") {   
      imagejpeg($img);
    } else if ($type == "image/x-png") {
      imagepng($img);
    } else if ($type == "image/gif") {
      imagegif($img);
    }
    imagedestroy($img);
    mysql_close($link);
};
?>

[cooldude832]

I've got this version working now, but I want to know how can I resize based on  height?

<?php
require_once("functions.php");
$id = $_GET['image_id'];
if(!empty($_GET['width'])){
$size = $_GET['width'];
}
else{
$size = 500;
}
if($id) {
connectSQL();
    $query = "select Image, ImageType from Images where ImageID = $id";
    $result = mysql_query($query) or die(mysql_error());
    $data = mysql_result($result,0,"Image");
    $type = mysql_result($result,0,"ImageType");
$type = "image/".$type;
    Header("Content-type: ".$type);   
    $src = imagecreatefromstring($data);
    $width = imagesx($src);
    $height = imagesy($src);
    $aspect_ratio = $height/$width;

    $new_w = $size;
    $new_h = abs($new_w * $aspect_ratio);


    $img = imagecreatetruecolor($new_w,$new_h);
    imagecopyresized($img,$src,0,0,0,0,$new_w,$new_h,$width,$height);
     // determine image type and send it to the client   
    if ($type == "image/pjpeg" || $type == "image/jpg" || type == "image/jpeg") {   
      imagejpeg($img);
    } else if ($type == "image/x-png" || $type = "image/png") {
      imagepng($img);
    } else if ($type == "image/gif") {
      imagegif($img);
    }
    imagedestroy($img);
}
?>

[Barand]

Decide the height you want.

Get the height it is now.

Scale the width by the same ratio.

 

Compared with partial differential equations, it's child's play

[cooldude832]

yeah, but I'm thinking its a bad idea because browsers have a set width (I don't like side scrolls) and an infinte  height so i'll just size in the height and if it doesn't fit my height needs I'll say scale it down more using a loop till i get numbers that manage. The width will be less than the desired, but it will suite my needs.

[elkidogz]

set either the width or the height as a standard (like all pics new height is 200) then do some math to work out what the width of the pic is, make a new pic from the old pic with the new height and new width and then put it into a folder.