[RESOLVED] ImageJPEG doesn't show image using <img src=.php>

nightqueen · Dec 12, 2007

echo "<img src='resize-image.php?image=".$filename."'>";

resize-image.php:

<?php

//destroy image first as the img tag that calls it is in a loop
ImageDestroy($src);
ImageDestroy($dst);

if (!$max_width)
$max_width = 150;
if (!$max_height)
$max_height = 100;

$size = GetImageSize($image)or die("Could not get image size");
$width = $size[0];
$height = $size[1];

$x_ratio = $max_width / $width;
$y_ratio = $max_height / $height;

if (($width <= $max_width) && ($height <= $max_height))
{
$tn_width = $width;
$tn_height = $height;
}
else if (($x_ratio $height) < $max_height)
{
$tn_width = $max_width;
$tn_height = ceil($x_ratio height);
echo "<br>tn_height: ".$tn_height;
}
else
{
$tn_width = ceil($y_ratio * $width);
$tn_height = $max_height;
}

$src = ImageCreateFromJpeg($image)or die("Could not create from Jpeg");
$dst = ImageCreateTrueColor($tn_width, $tn_height)or die("Could not create new image");
ImageCopyResized($dst, $src, 0,0,0,0, $tn_width, $tn_height, $width, $height)or die("Could not copy resized");

header('Content-type: image/jpg');
imagejpeg($dst, null, 75);
?>

However no image is returned. In firefox nothing and in IE just the red cross box. That box shows the image src as resize-image.php?

I've tried moving teh header around but it doesn't work at the top of resize-image.php or at the top of the page that calls it.

Any ideas?

Kudose · Dec 12, 2007

You are assuming register_globals in On.

Set $image ... don't just pull it out of thin air. Also, why are you destroying $src and $dst when they don't exist?

nightqueen · Dec 12, 2007

Register Globels is on.

I'm destroying $src and $dst because the <img> is in a loop and I wanted to make sure they were empty before creating them later in the script.

$filename contains the path of an image stored on the server. Before trying to resize the image I got it to display the original image and that worked so I know the address is correct.

I've tried
$src = ImageCreateFromJpeg($image)
and I've tried
$src = ImageCreateFromJpeg($_GET["image"])

Viewing the source of the page and copying resize-image.php... from the code and pasting it into the address bar shows up all the gibberish of the file with no error messages so I know it's creating the resized image.

I don't know why the <img> isn't displaying it though.

PartDigital · Dec 12, 2007

Can you post all of the code including the loop?

plus maybe you should do a check when you're destroying the image. For instance, at the top write

if($src) imagedestroy($src); 
if($dst) imagedestroy($dst);

I specialize in gdLibrary and I've written a few tutorials that may be helpful.

http://www.partdigital.com/tutorials/

in particular check out

http://www.partdigital.com/tutorials/use-gd/

nightqueen · Dec 12, 2007

This is included within an HTML page that contains other code including start_session() at the top and the template HTML for the page layout. This is inside a <td>.
It displays photos ordered by catagory with a header for each catagory. The images have been uploaded by a user and so will be large. I'm trying to display them as thumbnails that you can then click to display the large image. I'll add that code once I get the thumbnails to work.

<?php
// include the database connection
include ("Includes/connection.php");

$query = "SELECT photo, catagory FROM photos GROUP BY catagory";
$result = mysql_query($query,$db)or die("Could not complete query ".mysql_error());

while ($row = mysql_fetch_array($result))
{
$var = $row['catagory'];
echo "<h3>".$var."</h3>";
$query2 = "SELECT photo, username FROM photos, users WHERE catagory = '".$var."' AND photos.userID = users.userID";
$result2 = mysql_query($query2, $db)or die("<br>Could not query database2<br>".mysql_error());

echo "<table><tr>";
while ($row2 = mysql_fetch_array($result2))
{
	$image = "/var/www/vhosts/stoneycove.com/httpdocs/New Site/Images/Users Gallery/".$row2['photo'];
	echo "<td valign='bottom' align='center'><img src='resize-image.php?image=".$image."'><br>".$row2['username']."</td>";
}
echo "</tr></table>";

}
?>

This then points to resize-image.php which has the code I showed earlier:
<?php

//destroy image first as the img tag that calls it is in a loop
if ($src) ImageDestroy($src);
if ($dst) ImageDestroy($dst);

if (!$max_width)
$max_width = 150;
if (!$max_height)
$max_height = 100;

$size = GetImageSize($image)or die("Could not get image size");
$width = $size[0];
$height = $size[1];

$x_ratio = $max_width / $width;
$y_ratio = $max_height / $height;

if (($width <= $max_width) && ($height <= $max_height))
{
$tn_width = $width;
$tn_height = $height;
}
else if (($x_ratio $height) < $max_height)
{
$tn_width = $max_width;
$tn_height = ceil($x_ratio height);
echo "<br>tn_height: ".$tn_height;
}
else
{
$tn_width = ceil($y_ratio * $width);
$tn_height = $max_height;
}

$src = ImageCreateFromJpeg($image)or die("Could not create from Jpeg");
$dst = ImageCreateTrueColor($tn_width, $tn_height)or die("Could not create new image");
ImageCopyResized($dst, $src, 0,0,0,0, $tn_width, $tn_height, $width, $height)or die("Could not copy resized");

header('Content-type: image/jpg');
imagejpeg($dst, null, 75);
?>

PartDigital · Dec 12, 2007

did you check the url of the image in the browser?

for instance paste the following

"resize-image.php?image=/var/www/vhosts/stoneycove.com/httpdocs/New Site/Images/Users Gallery/myImage.jpg"

into the url and see what happens. You should see a resized version of your image in the browser. If not then something is wrong with your script.

nightqueen · Dec 12, 2007

OK, if I change the following bit of code

if (!$max_width)
$max_width = 150;
if (!$max_height)
$max_height = 100;

to

if (!$max_width)
$max_width = 200;
if (!$max_height)
$max_height = 150;

the direct url shows the reduced image.

If I set them both to 150 it says "Could not create new image".

The original test image is 210 x 148px

So I guess there's something wrong with my resize-image.php script. I copied it from SAMS PHP and MYSQL Web Development so I'm just trying to get my head around their if statements.

PartDigital · Dec 12, 2007

aaah I just got done writing a really thorough explanation and the damn thing logged me out and I lost it all!!!!!!

any way I basically said this. . .

Your problem seems to originate in the imagecreatetruecolor function.

http://us.php.net/imagecreatetruecolor

I don't recommend resizing images down to a square as they will get distorted (unless the image is as a square to begin with). I recommend that you crop them first. I have a tutorial that shows you how to do this.

http://www.partdigital.com/tutorials/gd-thumbnail

if you're doing this to learn php you might want to start with something more simple. gdLibrary can be pretty hard.

nightqueen · Dec 13, 2007

I'm doing this for work and am familiar with PHP but it is the first time I've tried to do any kind of image manipulation with PHP.

I thought that using the X_ratio and y_ratio variables meant that one side would be resized to a set size ($max_width or $max_height) and the other size would then be resized using the ratio variable ($X_ratio or $y_ratio multiplied by the $height or $width). I'm then creating an image based on these calculated results.

If I use ImageCreate without the TrueColor then the image doesn't display properly.

Scrub that. It appears to be working now.
Thanks.

And thanks for those turorials, they're great, really explained clearly. :-)

PartDigital · Dec 13, 2007

Yeah imagecreate is deprecated, you're better off using imagecreatetruecolor.

glad you got it to work, it can be a pain in the butt

nightqueen · Dec 13, 2007

Sure can! But it feels great when it finally works just the way you want it to. :-D

Thanks again.

[RESOLVED] ImageJPEG doesn't show image using <img src=.php>

Nnightqueen

KKudose

Nnightqueen

PPartDigital

Nnightqueen

PPartDigital

Nnightqueen

PPartDigital

Nnightqueen

PPartDigital

Nnightqueen