GD Image Library Example
Original JPG image
Resized JPG by target size
Buttons Using GD Fonts:
Vertical Text Bars using TrueType Fonts:
Original GIF image
Resized GIF by scale
Resized GIF to target max dim while maintaining aspect ratio
Testing Color Conversion Functions
Background Color FF0000 hex goes to (255,0,0) in RGB
Text Color 006633 hex goes to (0,102,51) in RGB
Source
The source code for this example page is:
...and the source code for the script called tba_resize_image.php that resizes an image based on a scaling factor is:
<?php
header("Content-type: image/jpeg");
Header("Content-type: image/png");
// we expect $scale and $image to be defined, having been passed to us via
// query string, e.g. http://www.foo.com/tba_resize_image.php?image=test.gif&scale=4
// create an image object from the source file
$srcImg = imagecreatefromgif($image);
// create a (blank) smaller image object
$srcSize = getimagesize($image);
$dstImg = imagecreate($srcSize[0]/$scale, $srcSize[1]/$scale);
// You can set up your image to be automatically made at the proper aspect ratio using this code:
$width = 200;
$height= 150;
$aspect_ratio = (imagesx($srcImg)/imagesy($srcImg));
if($aspect_ratio < ($width/$height))
{
$width = $height*$aspect_ratio;
} elseif($aspect_ratio > ($width/$height)) {
$height = $width/$aspect_ratio;
}
// copy and resize from the source image object to the smaller blank one
imagecopyresized($dstImg, $srcImg, 0, 0, 0, 0,
$srcSize[0]/$scale, $srcSize[1]/$scale,
$srcSize[0], $srcSize[1]);
// send the smaller image object to the browser
header("Content-Type: image/gif");
imagegif($dstImg);
// clean up
imagedestroy($scrImg);
imagedestroy($dstImg);
?>
...and the source code for the script called tba_resize_image.php that resizes an image based on a target size is:
does the work of generating a resized image is:
<?php
header("Content-type: image/jpeg");
Header("Content-type: image/png");
// we expect $scale and $image to be defined, having been passed to us via
// query string, e.g. http://www.foo.com/tba_resize_image.php?image=test.gif&scale=4
// create an image object from the source file
$srcImg = imagecreatefromgif($image);
// create a (blank) smaller image object
$srcSize = getimagesize($image);
$dstImg = imagecreate($srcSize[0]/$scale, $srcSize[1]/$scale);
// You can set up your image to be automatically made at the proper aspect ratio using this code:
$width = 200;
$height= 150;
$aspect_ratio = (imagesx($srcImg)/imagesy($srcImg));
if($aspect_ratio < ($width/$height))
{
$width = $height*$aspect_ratio;
} elseif($aspect_ratio > ($width/$height)) {
$height = $width/$aspect_ratio;
}
// copy and resize from the source image object to the smaller blank one
imagecopyresized($dstImg, $srcImg, 0, 0, 0, 0,
$srcSize[0]/$scale, $srcSize[1]/$scale,
$srcSize[0], $srcSize[1]);
// send the smaller image object to the browser
header("Content-Type: image/gif");
imagegif($dstImg);
// clean up
imagedestroy($scrImg);
imagedestroy($dstImg);
?>
