Creating photo thumbnails?

Question

I hate to use the "F" word, but in FrontPage I could use
Ctrl-T to change a photo on a page to a thumbnail, and it created
the link to the original.
How do I do this in DW CS3? I did Commands/Create Web Photo
Album, but that wants Fireworks. I can't afford to by FW now. Isn't
there a simpler way other than manuall creating the Thumbnails and
linking them to the originals?
I hate that I may have lost a function I used often in FP.
Gary

Answer 1

"Joris van Lier" <[email protected]> wrote:
>>"Clancy" <[email protected]> wrote
>> PHP has very good functions for manipulating photos,
including producing
>> thumbnails,
>
>Please do preferably with code examples that we can turn
into
>ServerBehaviors :)
The image manipulation facilities are a bit slow (6-10
seconds per set of 3
images), so I only use them to set up the working images on
my own PC, before I
upload them. I haven't tried running them on the remote
server. $quality is a
constant which determines the quality and degree of
compression of the new
image. 100 gives no compression, 80 gives a good-quality
image of reasonable
size, but anything much below 70 gives very obvious "ringing"
on things like
telegraph poles against a blue sky.
I don't know about 'ServerBehaviors', so you'll have to work
that out :)
Notice that in my example procedure I reset the time limit
for every new image.
I normally set this to 1, so I don't wait foreverwhen I write
the inevitable
infinite loop, but this way I don't time out halfway through,
but I don't wait
for ever if I do write an infinite loop.
These functions worked for me with php set up as instructed
by David Powers in
his book "PHP for Dreamweaver 8".
To get the EXIF information function working I had to
uncomment the lines:
extension=php_mbstring.dll (already included)
extension=php_exif.dll
in the file php.ini
A. Shrink image.
<?php
// Set up $orig_image as full path/file name of image to be
reduced
// eg Flowers/Orchids/Diuris/DSCN1055.JPG
// 1. Create an image object (presumably a bit map?) from it.
$wkg_image = imagecreatefromjpeg($orig_image); // Working
copy of original
image
// 2. Get original size
$size = getimagesize ($orig_image); // Get dimensions
// 3. Decide new dimensions (the magic numbers used here are
explained in the
example below)
$height = $scale[$k][0]; $width = (int) ($height*$ratio);
// 4. Decide where to put target. Again full path/filename
$target = $path.$image;
// 5. Create a temporary image object the size of the new
image.
$temp_image = imagecreatetruecolor($width, $height);
// 6. Resample the image into the new object (if you replace
the zeroes with
offsets you can specify a portion of the image to be sampled
-- I haven't tried
this)
imagecopyresampled($temp_image, $wkg_image, 0, 0, 0, 0,
$width, $height,
$size[0], $size[1]);
// 7. Convert it to JPEG
imagejpeg($temp_image, $target, $quality);
// 8. Discard the temporary images.
imagedestroy($temp_image);
imagedestroy($wkg_image);
// Done!
B. Procedure to list all EXIF (image header data). I'm not
too sure how this
works, but it does! (Comes from the manual.)
// Specify source file
$old_image = 'Dev/Original/DSCN0389.jpg';
echo '<p>T:153. Trying to read data from
'.$old_image.'</p>';
$exif = exif_read_data($old_image, 0, true);
echo "T:157 '.$old_image.':<br />\n";
foreach ($exif as $key => $section)
foreach ($section as $name => $val)
echo "$key.$name: $val<br />\n";
C. Actual procedure to scan directory, get updated files, and
generate large,
medium and thumbnail images meeting specific size
constraints. (Large fits
nicely on 1280*1024 screen, Medium on 1024*768 screen.)
// (This is not written as a procedure, just included when
needed. It is
included purely to show you an actual working example using
these functions)
// 23/10/07 Created
$get_img = array (false, false, false);//
$changed = false;
$quality = array (80, 80, 75);
$img_dirs = array ( 'Large/', 'Images/', 'Thumbs/' );
$pattern = ".jpg"; // I only want .JPG images
// Apply different algorithms according to shape of image and
required size.
$limits = array (
0 => array ( 1.05, 1.61 ), // Large image
1 => array ( 1.0, 1.725 ), // Normal image
2 => array ( 0.1, 1.125 )); // Thumb
$scale = array (
0 => array ( 830, 770, 1240), // Maximum dimensions
(Height for portrait, then
landscape, then width for superwide)
1 => array ( 610, 550, 950),
2 => array ( 160, 160, 180));
// See which sizes have been requested.
if (array_key_exists('ck_l', $_POST)) { $get_img[0] = true; }
//echo
'<p>Im_2_22: $get_img[0] = true</p>';}
if (array_key_exists('ck_m', $_POST)) { $get_img[1] = true; }
//echo
'<p>Im_2_23: $get_img[1] = true</p>'; }
if (array_key_exists('ck_t', $_POST)) { $get_img[2] = true; }
//echo
'<p>Im_2_24: $get_img[2] = true</p>'; }
// Abandon if 'Cancel' set.
if (array_key_exists('cancel', $_POST))
$edit_data['action'] = 0; $edit_data['ind_act'] = 0;
$changed = 0;
else
$dir = $edit_data['f_path'].'Original';
//echo ('<p>Im_2_34: Trying to open
'.$dir.'</p>');
f (is_dir($dir))
if ($dh = opendir($dir))
//echo "<p>Im_2_39: ".$dir." opened OK.</p>";
while (($image = readdir ($dh)) !== false)
$orig_image = $dir.'/'.$image;
if (stristr ($orig_image, $pattern))
//echo "<p>Im_2_46: Next image =
".$orig_image."</p>";
$src_date = date ("ymdhis",filectime($orig_image)); // Get
date file
updated
set_time_limit(4);
// Got an image. K = 0 (large), 1 (normal), 2 (thumb)
// See if already present, and later version
$wanted = false;
$k = 0; while (($k < 3) && (!$wanted))
$w[$i] = false;
if ($get_img[$k]) // Want this size?
$target = $edit_data['f_path'].$img_dirs[$k].$image;
if ((!file_exists($target) || (date
("ymdhis",filectime($target))
<= $src_date)))
$wanted = true; $w[$k] = true;
$k++;
if ($wanted)
$wkg_image = imagecreatefromjpeg($orig_image); // Working
copy of
original image
$size = getimagesize ($orig_image); // Get dimensions
$ratio = $size[0]/$size[1]; // Calc ratio of width to height
echo '<p>Im_2_72: Size = '.$size[0].', '.$size[1].',
'.$ratio.'</p>';
$k = 0; while ($k < 3)
if ($w[$k]) // Want this size?
if ($ratio > $limits[$k][0])
if ($ratio > $limits[$k][1])
$width = $scale[$k][2]; $height = (int) ($width/$ratio);
else
$height = $scale[$k][1]; $width = (int) ($height*$ratio);
else
$height = $scale[$k][0]; $width = (int) ($height*$ratio);
$target = $edit_data['f_path'].$img_dirs[$k].$image;
echo '<p>Im_2_76: $k = '.$k.', Width = '.$width.',
Height = '.$height.', orig:
'.$size[0].' * '.$size[1].', Target = '.$target.'</p>';
$temp_image = imagecreatetruecolor($width, $height);
imagecopyresampled($temp_image, $wkg_image, 0, 0, 0, 0,
$width, $height,
$size[0], $size[1]);
imagejpeg($temp_image, $target, $quality[$k]);
imagedestroy($temp_image);
$k++;
imagedestroy($wkg_image);
$changed = 1; // Magic numbers for my program
$edit_data['action'] = 0; // Flag file written correctly
$edit_data['ind_act'] = 2; // Generate index logical next
step
?>
Clancy