Thumbnail Image generation

adrian_quah

Hallo! Can u please tell me how i can create a thumbnail for an image...say of size '90 times 90' pixels from an existing image and save it in the same folder. I've got the GD library running on my PC..Just need some help 2 get started..

Any help is a help 🙂 Thanks.

blanius

Here is a code snippet from one of our sites
it sets the thumbnail to 1/4 size you could just use 90 instead of the calculations.

 
//Generate Thumbnail
				$src=ImageCreateFromJpeg($filename);
				$swidth=ImageSx($src);
				$sheight=ImageSy($src);
				$dwidth=$swidth*.25;
				$dheight=$sheight*.25;
				$dst=ImageCreateTrueColor($dwidth,$dheight);
				ImageCopyResampled($dst,$src,0,0,0,0,$dwidth,$dheight,$swidth,$sheight);
				ImageJpeg($dst,$thumbname);
				ImageDestroy($src);
				ImageDestroy($dst);

brooky

Hi I get this message:

Fatal error: imagecreatetruecolor(): requires GD 2.0 or later in /home/sites/site13/web/demo_store/images/makethumb.php on line 8

Is there another way to do this as my shared server only supports GD v1.6.2?

trooper

Hmm your gonna be a little bit stuck then if you don't have gd installed on the live server

Is it essential to have a new image as the thumbnail?

The reason i ask is cause i'm writing an image gallery and came across the same issue.

Whilst my development box has all the extensions that you could wish for but i can't guarentee that live servers will

So my answer to this conundrum was this:

If the server doesn't have the requirements then i'll simply use html by specifying either the height or width or the image) to resize the image and have that appear as the thumbnail. Now i know its not the answer as the image is still the same file ,but aside from making it only work on specific servers (which will drastically reduce its portability) that have the requirements what else can you do?

TIP: Always make sure that your code works on servers that only have "vanilla" php installations.

HTH

brooky

Hi sorry I think I must have been editing my post when you replied. I do have version 1.6 of GD on the server which has png, gif and jpg enabled.

Do you know anywhere that can help me work with this old version?

xeq

use imagecreate and imagecopyresized instead (but thumbnail quality will drop)

adrian_quah

Actually, i'd like to have a script that generates thumbnail images from deriving a certain ammount (say 90 times 90 pixels) from the center of a say 200 times 200 pix image.

Any help is greatly appreciated.

blanius

Originally posted by adrian_quah
Actually, i'd like to have a script that generates thumbnail images from deriving a certain ammount (say 90 times 90 pixels) from the center of a say 200 times 200 pix image.

Any help is greatly appreciated.

This same function can do that
http://www.php.net/manual/en/function.imagecopyresampled.php

basicaly the above line you just specify where in the soucre file you want to start copying and the height and width.....

So the following should work:UNTESTED!!!!

//Generate Thumbnail
//modified to take 90x90 centered clip form origianl
                $src=ImageCreateFromJpeg($filename);
                $swidth=ImageSx($src);
                $sheight=ImageSy($src);
                $dwidth=90;
                $dheight=90;
                $left=($swidth/2)-($dwidth/2);
                $top=($sheight/2)-($dheight/2);
                $dst=ImageCreateTrueColor($dwidth,$dheight);
                 ImageCopyResampled($dst,$src,0,0,$left,$top,$dwidth,$dheight,$swidth,$sheight);
                ImageJpeg($dst,$thumbname);
                ImageDestroy($src);
                ImageDestroy($dst);

blanius

The server I tested this one couldn't handle the 2.0 image stuff so here is a version that I actually tested.

<?php
//Generate Thumbnail
//modified to take 90x90 centered clip form origianl
Header ("Content-type: image/jpeg");
$filename=$_GET['file'];
                $src=ImageCreateFromJpeg($filename);
                $swidth=ImageSx($src);
                $sheight=ImageSy($src);
                $dwidth=90;
                $dheight=90;
                $left=($swidth/2)-($dwidth/2);
                $top=($sheight/2)-($dheight/2);
                $dst=ImageCreate($dwidth,$dheight);
                 ImageCopy($dst,$src,0,0,$left,$top,$swidth,$sheight);
                ImageJpeg($dst);
                ImageDestroy($src);
                ImageDestroy($dst);

            ?>

adrian_quah

Thanks Blanius...but i was wondering how the values of $filename and $dstare...

Would the following be valid: -

<?php
$filename = "today.jpg";
$dst = "thumbnail_of_today.jpg";
?>

How can i assign my own name for the thumbnail generated and save it?

Thanks real lot again 😃

blanius

Originally posted by adrian_quah
Thanks Blanius...but i was wondering how the values of $filename and $dstare...

Would the following be valid: -
<?php
$filename = "today.jpg";
$dst = "thumbnail_of_today.jpg";
?>
How can i assign my own name for the thumbnail generated and save it?

Thanks real lot again 😃 [/B]

Not quite. You cannot name the $dst variable... the above does not save anything to the server just puts it in the browser.

To save it change the following line
ImageJpeg($dst);

to ImageJpeg($dst,$yourfilename);

Note the HEADER function at the top, this tells the browser that it's getting an image file, not an HTML file. So if you don't want to send the generated image directly to the browser you need to remove that line.

We have a gallery code that does just that, it generates the thumbnail and description file as a timestamp filename and saves them to the server in a gallery folder, the display page just looks through the gallery folder and displays all the Jpg that start with 'thmb'.

dleone

IS this code compatible with GD 1.8.4:

Here is a code snippet from one of our sites
it sets the thumbnail to 1/4 size you could just use 90 instead of the calculations.

PHP:--------------------------------------------------------------------------------
//Generate Thumbnail
$src=ImageCreateFromJpeg($filename);
$swidth=ImageSx($src);
$sheight=ImageSy($src);
$dwidth=$swidth.25;
$dheight=$sheight.25;
$dst=ImageCreateTrueColor($dwidth,$dheight);
ImageCopyResampled($dst,$src,0,0,0,0,$dwidth,$dheight,$swidth,$sheight);
ImageJpeg($dst,$thumbname);
ImageDestroy($src);
ImageDestroy($dst);

Bret
swsinternet.com
bretlanius.com

blanius

No! This is gd2+ look in my other post in this thread there is a version that I tested on a server that is running something like 1.6. Mainly the difference is the truecolor and resample are not supported in the older versions of GD

dleone

WHHOOPS: meant this one.; can I can use this with a form that grabs an uploaded image in this manner, pass it to this function in some way and return a second image, the thumbnail?

calilng it like this:

$filename = ($FILES["image"]["tmp_name"][0]);

<?php
//Generate Thumbnail
//modified to take 90x90 centered clip form origianl
Header ("Content-type: image/jpeg");
$filename=$_GET['file'];
$src=ImageCreateFromJpeg($filename);
$swidth=ImageSx($src);
$sheight=ImageSy($src);
$dwidth=90;
$dheight=90;
$left=($swidth/2)-($dwidth/2);
$top=($sheight/2)-($dheight/2);
$dst=ImageCreate($dwidth,$dheight);
ImageCopy($dst,$src,0,0,$left,$top,$swidth,$sheight);
ImageJpeg($dst);
ImageDestroy($src);
ImageDestroy($dst);

?>

blanius

Yes but the code you are quoting doesn't save the image. You should put a filename to save to in the line

ImageJpeg($dst,$thumbname);

where $thumbname is the file to save the thumbnail to.

dleone

Thanks - geting an invalid file name error. I am actually at the end of the page then trying to place this image with others in a mysql database. here's the code snippet:
$src=ImageCreateFromJpeg($FILES["image"]["tmp_name"][0]);
$swidth=ImageSx($src);
$sheight=ImageSy($src);
$dwidth=100;
$dheight=100;
$dst=ImageCreate($dwidth,$dheight);
ImageCopyResized($dst,$src,0,0,0,0,$dwidth,$dheight,$swidth,$sheight);
ImageJpeg($dst,$createdthumb);
ImageDestroy($src);
ImageDestroy($dst);

 $file = fopen($_FILES["$createdthumb"]["tmp_name"], "r");
  	$createdthumb = 
      fread($file, $createdthumb["size"]); 
   // Escape special charcters in the file
    $createdthumb = AddSlashes($createdthumb);

 $visible=1;
 $security=100;


 $insertQuery = "INSERT INTO remains VALUES (NULL, " .
                "\"" . $title . "\", " .
                "\"" . $description . "\", " .
                "\"" . $price . "\", " .
                "\"" . $ship . "\", " .
                "\"" . $fileContents[0] . "\" , " .
                "\"" . $fileContents[1] . "\" , " .
                "\"" . $fileContents[2] . "\" , " .

// "\"" . $fileContents[3] . "\" , " .

"\"" . $createdthumb . "\" , " .

"\"" . $category . "\", " .
"\"" . $legacy_id . "\", " .
"\"" . $visible . "\", " .

                "\"" . $security . "\")";

matto

I use mogrify for that; it's included in the imagemagick toolkit www.imagemagick.org

I like it because it's very simple. after you have installed mogrify on your (linux) server, call this function:

function resizepic($filename, $x, $y)
{
        if($filename != '' && is_file($filename))
        {
                $command = "mogrify -geometry ".$x."x".$y." $filename";
                passthru($command);
        }
}

nearly the same for cropping pics:

function croppic($filename, $x, $y)
{
        if($filename != '' && is_file($filename))
        {
                $command = "mogrify -crop ".$x."x".$y." $filename";
                passthru($command);
        }
}

hope this helps!

dleone

Thanks. I appreciate your help. However, I am trying to do this so this entire script can be ported to the most generic php installations --- used on any webhost.
I need away to pass the created image to mysql query for uploading.
-thanks again,
Don

blanius

Originally posted by dleone
Thanks - geting an invalid file name error. I am actually at the end of the page then trying to place this image with others in a mysql database. here's the code snippet:

$file = fopen($_FILES["$createdthumb"]["tmp_name"], "r");
$createdthumb =
fread($file, $createdthumb["size"]);
// Escape special charcters in the file
$createdthumb = AddSlashes($createdthumb);

Looks like your using the same variable for two things, The file name and the file contents... then you add slashes to the file contents.....

I never store the actual thumbnail I just store the path to it that is in the $createdthumb before the above code is executed.

Also you seem to be trying to use the $_FILES array which the thumbnail would not be there, you saved it to somewhere in the other code with this line:

ImageJpeg($dst,$createdthumb);

dleone

Bret I have tried various methods and changes but still get the error on the line that says:

  					 ImageJpeg($dst,$createdthumb);

I have tried variations on this. I don't care if the file gets saved - I just want to get the thumb to be in a variable I can pass to the insert string:

insertQuery = "INSERT INTO remains VALUES (NULL, " .
"\"" . $title . "\", " .
"\"" . $description . "\", " .
"\"" . $price . "\", " .
"\"" . $ship . "\", " .
"\"" . $fileContents[0] . "\" , " .
"\"" . $fileContents[1] . "\" , " .
"\"" . $fileContents[2] . "\" , " .
// "\"" . $fileContents[3] . "\" , " .
"\"" . $createdthumb . "\" , " .
"\"" . $category . "\", " .
"\"" . $legacy_id . "\", " .
"\"" . $visible . "\", " .
"\"" . $security . "\")";

I've attached the entire php page saved as a 'txt'. to help illustrate. Also, the db.inc pulls the UID, PW and clean.inc cleans up the field link to stop hackers at the browser. I didn't attach them. The other include is not needed, only if I put this in a function.