image resize

[lional]

Hi All

I am writing an application where one page uploads an image to my webserver. I would like the next page to display that image but making it smaller to fit on the page but I would still like the image to be in proportion. Is this poissible in PHP

 

Thanks

 

Lional

[ratcateme]

have a look at this

http://nz.php.net/manual/en/function.imagecopyresized.php

look at the first example

you can calculate the percentage.

then run that code and it will downsize your image

 

Scott.

[lional]

Is there a way to get the dimensions (width and length) of the file we are uploading. The image that gets uploaded will differ depending on the image that the user uploads. I know how to get the file size in Kb or Mb.

[JasonLewis]

Have a look at getimagesize() to get the width and height of an image.

 

To resize an image that is greater then a set width or height you can use this:

 

<?php

list($width, $height) = getimagesize("image.jpg");

$maxWidth = 300;
$maxHeight = 500;

//First check if the image has greater width or height then the maximums
if($width > $maxWidth || $height > $maxHeight){

//If you haven't specified a max width because you are only constraining the height, then we set the widthDivision as the width of the image.
if($maxWidth == ""){
	$widthDivision = $width;
}else{
//If maxWidth is specified, we set the width division as the maxWidth divide by the width of the image.
	$widthDivision = $maxWidth/$width;
}

//Same for height as was said in the width.
if($maxHeight == ""){
	$heightDivision = $height;
}else{
	$heightDivision = $maxHeight/$height;
}

//Now the brains, the min function. Get the lowest number out of the width and height.
$MIN = min($widthDivision, $heightDivision);

//Now we can set the new widths and height by multiplying the lowest number into both the original width and height. This will constrain the proportions...
$newWidth = $MIN*$width;
$newHeight = $MIN*$height;
}else{
//If the image is fine, just set the new width and height as the default.
$newWidth = $width;
$newHeight = $height;
}
?>

[lional]

The image seems to depixulate

 

Any Ideas

 

Thanks

 

Lional

[blinky001]

http://nz.php.net/manual/en/function.imagecopyresampled.php

 

This is a far better function - I never use imageCopyRezised for just this reason. Resampling does take more memory though...

[lional]

I have tried using this but I get "garbage" printing out instead of my image

Here is my code

$effects_image = $_SESSION['photo'];

  list($width, $height) = getimagesize("$effects_image");

  $maxWidth = 256;

  $maxHeight = 256;

  if ($width > $maxwidth || $height > $maxheight) {

  //If you haven't specified a max width because you are only constraining the height, then we set the widthDivision as the width of the image.

if($maxWidth == ""){

$widthDivision = $width;

}else{

//If maxWidth is specified, we set the width division as the maxWidth divide by the width of the image.

$widthDivision = $maxWidth/$width;

}

 

//Same for height as was said in the width.

if($maxHeight == ""){

$heightDivision = $height;

}else{

$heightDivision = $maxHeight/$height;

}

 

//Now the brains, the min function. Get the lowest number out of the width and height.

$MIN = min($widthDivision, $heightDivision);

 

//Now we can set the new widths and height by multiplying the lowest number into both the original width and height. This will constrain the proportions...

$newWidth = $MIN*$width;

$newHeight = $MIN*$height;

}else{

//If the image is fine, just set the new width and height as the default.

$newWidth = $width;

$newHeight = $height;

 

}

 

 

// Resample

$image_p = imagecreatetruecolor($newWidth, $newHeight);

$image = imagecreatefromjpeg($effects_image);

imagecopyresampled($image_p, $image, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);

 

// Output

imagejpeg($image_p, null, 100);

[ratcateme]

add this somewhere

header('Content-Type: image/jpeg');

 

Scott.

[lional]

It has been added to the top of my page, still have the same problem

[beedie]

there mustn't be any content at all before the

header('Content-Type: image/jpeg');

if there needs to be which is likely you will need to use ob_start() and ob_flush() .

[lional]

I have this code on the top of my page

ob_flush();ob_start();

header('Content-type: image/jpeg');

  session_start();

[ratcateme]

what is the buffering for??

 

Scott.

[lional]

I was going on what beedie said because I just get garbage on the screen it is not displaying the image and I don't know why.

[ratcateme]

i have never found that i need that but i would recommend placing it on the line above

imagejpeg($image_p, null, 100);

 

Scott.

[beedie]

Did you get it sorted?

 

 

<?php
///your image generation code ending with(change the file name to the file name and path you want):
imagejpeg($image_p, savepath/image_name.jpg, 100);
echo '<img src="savepath/image_name.jpg" />';

//that create the image tag and you needn't worry about the headers, sessions, output bufferring etc.
?>