optimizing my gallery scripting..

GeX

GeX

GeX

Soldato
Joined
17 Dec 2002
Posts
6,981
Location
Manchester
Hi

I've been slowly learning php/css/etc over the last few months, and have put together a site. It has photo gallery sections on it, and whilst the coding i've done works - i know it is not ideal.

It auto adds images from a directory, creates a link to them image for lightbox, using the directory name as 'rel' and reads the exif data to create a caption to be displayed in lightbox. That bit is fine, but it also creates a thumbnail of the image, adds that to the gallery index and uses the exif data as the alt text.

Like i say it works, and does exactly what i want. However, everytime the page is loaded, it is generating thumbnails. Which is slow, and not great for server load.

How can i get it to cache the thumbnails? I did not write the script that is resizing the images, i will post it below.

Code: 
<?php
header ("Content-type: image/jpeg");
/*
JPEG / PNG Image Resizer
Parameters (passed via URL):

img = path / url of jpeg or png image file

percent = if this is defined, image is resized by it's
          value in percent (i.e. 50 to divide by 50 percent)

w = image width

h = image height

constrain = if this is parameter is passed and w and h are set
            to a size value then the size of the resulting image
            is constrained by whichever dimension is smaller

Requires the PHP GD Extension

Outputs the resulting image in JPEG Format

By: Michael John G. Lopez - www.sydel.net
Filename : imgsize.php
*/

$img = $_GET['img'];
$percent = $_GET['percent'];
$constrain = $_GET['constrain'];
$w = $_GET['w'];
$h = $_GET['h'];

// get image size of img
$x = @getimagesize($img);
// image width
$sw = $x[0];
// image height
$sh = $x[1];

if ($percent > 0) {
	// calculate resized height and width if percent is defined
	$percent = $percent * 0.01;
	$w = $sw * $percent;
	$h = $sh * $percent;
} else {
	if (isset ($w) AND !isset ($h)) {
		// autocompute height if only width is set
		$h = (100 / ($sw / $w)) * .01;
		$h = @round ($sh * $h);
	} elseif (isset ($h) AND !isset ($w)) {
		// autocompute width if only height is set
		$w = (100 / ($sh / $h)) * .01;
		$w = @round ($sw * $w);
	} elseif (isset ($h) AND isset ($w) AND isset ($constrain)) {
		// get the smaller resulting image dimension if both height
		// and width are set and $constrain is also set
		$hx = (100 / ($sw / $w)) * .01;
		$hx = @round ($sh * $hx);

		$wx = (100 / ($sh / $h)) * .01;
		$wx = @round ($sw * $wx);

		if ($hx < $h) {
			$h = (100 / ($sw / $w)) * .01;
			$h = @round ($sh * $h);
		} else {
			$w = (100 / ($sh / $h)) * .01;
			$w = @round ($sw * $w);
		}
	}
}

$im = @ImageCreateFromJPEG ($img) or // Read JPEG Image
$im = @ImageCreateFromPNG ($img) or // or PNG Image
$im = @ImageCreateFromGIF ($img) or // or GIF Image
$im = false; // If image is not JPEG, PNG, or GIF

if (!$im) {
	// We get errors from PHP's ImageCreate functions...
	// So let's echo back the contents of the actual image.
	readfile ($img);
} else {
	// Create the resized image destination
	$thumb = @ImageCreateTrueColor ($w, $h);
	// Copy from image source, resize it, and paste to image destination
	@ImageCopyResampled ($thumb, $im, 0, 0, 0, 0, $w, $h, $sw, $sh);
	// Output resized image
	@ImageJPEG ($thumb);
}
?>
 
edit: completely changed my mind about this. try this instead.... :p

Code: 
<?php
header ("Content-type: image/jpeg");
/*
JPEG / PNG Image Resizer
Parameters (passed via URL):

img = path / url of jpeg or png image file

percent = if this is defined, image is resized by it's
          value in percent (i.e. 50 to divide by 50 percent)

w = image width

h = image height

constrain = if this is parameter is passed and w and h are set
            to a size value then the size of the resulting image
            is constrained by whichever dimension is smaller

Requires the PHP GD Extension

Outputs the resulting image in JPEG Format

By: Michael John G. Lopez - [url]www.sydel.net[/url]
Filename : imgsize.php
*/
$prefix = 'th_';
$img = $_GET['img'];

[B]if(file_exists($prefix.$img)) {
    readfile($prefix.$img);
    exit;
}[/B]

$percent = $_GET['percent'];
$constrain = $_GET['constrain'];
$w = $_GET['w'];
$h = $_GET['h'];

// get image size of img
$x = @getimagesize($img);
// image width
$sw = $x[0];
// image height
$sh = $x[1];

if ($percent > 0) {
	// calculate resized height and width if percent is defined
	$percent = $percent * 0.01;
	$w = $sw * $percent;
	$h = $sh * $percent;
} else {
	if (isset ($w) AND !isset ($h)) {
		// autocompute height if only width is set
		$h = (100 / ($sw / $w)) * .01;
		$h = @round ($sh * $h);
	} elseif (isset ($h) AND !isset ($w)) {
		// autocompute width if only height is set
		$w = (100 / ($sh / $h)) * .01;
		$w = @round ($sw * $w);
	} elseif (isset ($h) AND isset ($w) AND isset ($constrain)) {
		// get the smaller resulting image dimension if both height
		// and width are set and $constrain is also set
		$hx = (100 / ($sw / $w)) * .01;
		$hx = @round ($sh * $hx);

		$wx = (100 / ($sh / $h)) * .01;
		$wx = @round ($sw * $wx);

		if ($hx < $h) {
			$h = (100 / ($sw / $w)) * .01;
			$h = @round ($sh * $h);
		} else {
			$w = (100 / ($sh / $h)) * .01;
			$w = @round ($sw * $w);
		}
	}
}

$im = @ImageCreateFromJPEG ($img) or // Read JPEG Image
$im = @ImageCreateFromPNG ($img) or // or PNG Image
$im = @ImageCreateFromGIF ($img) or // or GIF Image
$im = false; // If image is not JPEG, PNG, or GIF

if (!$im) {
	// We get errors from PHP's ImageCreate functions...
	// So let's echo back the contents of the actual image.
	readfile ($img);
} else {
	// Create the resized image destination
	$thumb = @ImageCreateTrueColor ($w, $h);
	// Copy from image source, resize it, and paste to image destination
	@ImageCopyResampled ($thumb, $im, 0, 0, 0, 0, $w, $h, $sw, $sh);
	// Output resized image
	@ImageJPEG ($thumb[B], $prefix.$img[/B]);
}
?>

changes in bold.
 
Last edited:
just this part?

Code: 
if(file_exists($prefix.$img)) {
    readfile($prefix.$img);
    exit;
}

by creating thumbs in the same directory though, next time the page loads, it will make thumbs of the thumbs and add them too?
 
edit: updated script to write thumbs to their own directory. you'll need to manually create a "thumbs" folder....

Code: 
<?php
header ("Content-type: image/jpeg");
/*
JPEG / PNG Image Resizer
Parameters (passed via URL):

img = path / url of jpeg or png image file

percent = if this is defined, image is resized by it's
          value in percent (i.e. 50 to divide by 50 percent)

w = image width

h = image height

constrain = if this is parameter is passed and w and h are set
            to a size value then the size of the resulting image
            is constrained by whichever dimension is smaller

Requires the PHP GD Extension

Outputs the resulting image in JPEG Format

By: Michael John G. Lopez - www.sydel.net
Filename : imgsize.php
*/

$img = $_GET['img'];
$thumbs = 'thumbs/';
if(file_exists($thumbs.$img)) {
	readfile($thumbs.$img);
	exit;
}

$percent = $_GET['percent'];
$constrain = $_GET['constrain'];
$w = $_GET['w'];
$h = $_GET['h'];

// get image size of img
$x = @getimagesize($img);
// image width
$sw = $x[0];
// image height
$sh = $x[1];

if ($percent > 0) {
	// calculate resized height and width if percent is defined
	$percent = $percent * 0.01;
	$w = $sw * $percent;
	$h = $sh * $percent;
} else {
	if (isset ($w) AND !isset ($h)) {
		// autocompute height if only width is set
		$h = (100 / ($sw / $w)) * .01;
		$h = @round ($sh * $h);
	} elseif (isset ($h) AND !isset ($w)) {
		// autocompute width if only height is set
		$w = (100 / ($sh / $h)) * .01;
		$w = @round ($sw * $w);
	} elseif (isset ($h) AND isset ($w) AND isset ($constrain)) {
		// get the smaller resulting image dimension if both height
		// and width are set and $constrain is also set
		$hx = (100 / ($sw / $w)) * .01;
		$hx = @round ($sh * $hx);

		$wx = (100 / ($sh / $h)) * .01;
		$wx = @round ($sw * $wx);

		if ($hx < $h) {
			$h = (100 / ($sw / $w)) * .01;
			$h = @round ($sh * $h);
		} else {
			$w = (100 / ($sh / $h)) * .01;
			$w = @round ($sw * $w);
		}
	}
}

$im = @ImageCreateFromJPEG ($img) or // Read JPEG Image
$im = @ImageCreateFromPNG ($img) or // or PNG Image
$im = @ImageCreateFromGIF ($img) or // or GIF Image
$im = false; // If image is not JPEG, PNG, or GIF

if (!$im) {
	// We get errors from PHP's ImageCreate functions...
	// So let's echo back the contents of the actual image.
	readfile ($img);
} else {
	// Create the resized image destination
	$thumb = @ImageCreateTrueColor ($w, $h);
	// Copy from image source, resize it, and paste to image destination
	@ImageCopyResampled ($thumb, $im, 0, 0, 0, 0, $w, $h, $sw, $sh);
	// Output resized image
	@ImageJPEG ($thumb, $thumbs.$img);
}
?>
 
Last edited:
okie kokie. that creates the thumbnails and stores them where i'd expect, but on the first run of the script, it won't display the image.

if i reload, then it will display the thumbnail. but if i delete the thumb and then reload, it'll just display the string thats meant to locate the thumbnail, ie just

Code: 
http://tackycheese.net/dev/v2/imgsize.php?w=150&h=100&img=test/4.jpg

edit.. what a difference a cup of coffee makes. added this to the end again;

Code: 
@ImageJPEG ($thumb);

now as far as i can tell, it only output using that if the thumbnail isnt there.

no.. it won't. doh.

surely it should be dropping out when it realises the file is already there, and so isn't running the rest of it? why would adding that line back at the end cause it redraw the image by resizing the origonal :confused:
 
Last edited:
GeX said:
Code: 
@ImageJPEG ($thumb);
Click to expand...

add that line after my last line of code so it reads......

Code: 
//this writes to disk
@ImageJPEG ($thumb, $thumbs.$img);
//this outputs to screen
@ImageJPEG ($thumb);

just noticed this script isn't using imagedestroy - that infact should be the last line. add this to the end......

Code: 
imagedestroy($thumb);
 
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