Draw IplImage
OpenCV stores images in a data structure called IplImage. They provide methods for rendering it to the screen, but if you want to use OpenGL instead (which should be faster and gives you more flexibility), I wrote the following code. It should be a little faster than loading the IplImage into a texture first, and then drawing it (if you have to do this every frame).
{
GLenum format;
switch(image->nChannels) {
case 1:
format = GL_LUMINANCE;
break;
case 2:
format = GL_LUMINANCE_ALPHA;
break;
case 3:
format = GL_BGR;
break;
default:
return;
}
glRasterPos2i(x, y);
glPixelZoom(xZoom, yZoom);
glDrawPixels(image->width, image->height, format, GL_UNSIGNED_BYTE, image->imageData);
}
It should be pretty straight forward to use. Handles IplImages with 1 or 3 layers. Should work with 2 layers too, but I haven't needed or found an example of this.
Get frame count from AVI
Here's a little code snippet I wrote to get the number of frames in an AVI video file.
// only works on AVIs
int frameCount;
char size[4];
ifstream fin(filename, ios::in|ios::binary);
if(!fin) {
cerr << "Could not open " << filename << endl;
exit(EXIT_FAILURE);
}
fin.seekg(0x30, ios::beg); // number of frames is stored at this location
fin.read(size, 4);
frameCount = size[0] | size[1]<<8 | size[2]<<16 | size[3]<<24;
fin.close();
return frameCount;
}
Use it however you like. I'm using it because OpenCV's cvGetCaptureProperty doesn't seem to work.
Templating with PHP
There are two main ways to create templates with PHP.
Header/Footer Files
First, design a one-page static layout for your site. You should come up with something like this:
<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
<head>
<title>Untitled</title>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
<meta name="keywords" content="" />
<meta name="description" content="" />
<link rel="shortcut icon" type="image/x-icon" href="/favicon.ico" />
<link rel="stylesheet" type="text/css" href="/style.css" />
</head>
<body>
<div id="page-wrap">
<ul id="navbar">
<li><a href="first-link">First Page</a></li>
<li><a href="second-link">Second Page</a></li>
</ul>
<div id="main-area">
<a id="logo" href="/"></a>
<div id="content-container">
<div id="content-body">
PAGE-CONTENT-HERE
</div>
</div>
</div>
<div id="footer">
<p>yoursite.com © <?=date('Y')?> | <a href="/privacy-policy">Privacy Policy</a></p>
</div>
</div>
</body>
</html>
Now, take everything above "PAGE-CONTENT-HERE" and throw it in a file like "header.inc.php". Take the bottom half and put it in "footer.inc.php". Now for each page, you can do something like this:
include 'header.inc.php';
echo <<<HTML
<h2>Page Title</h2>
<p>Page content.</p>
HTML;
include 'footer.inc.php';
?>
Now, if you ever want to change the appearance of your site, you just need to edit your header or footer files!
The advantage of this method is that you can put PHP scripts before you include the header, or make special pages different by using a different header/footer.
Include Method
For this method, you can use the same page layout as above (save it as index.php), but replace PAGE-CONTENT-HERE with something like this:
include $_GET['p'].'.php';
?>
And then make all your links like <a href="/?p=mypage">. You have to very careful if you use this method though, because malicious users can include whatever they want into your layout! Imagine what would happen if they went to "yoursite.com/?p=index" for example (you'd have a page inside a page inside a page...). Or ?p=http://malicioususer.com/evilscript.
The advantage of using this method is that you don't have to include a header and footer in each one of your content pages, but you get less flexibility over the layout of your site for special pages.
The Hybrid Method
This method gives you the best of both worlds, although it is perhaps ever so slightly more processor intensive. For this method, you will need create a .htaccess file like this:
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule .* /?p=$0
Well, I guess you don't really need to, but it will make your URLs prettier (no file extensions).
Then create an index.php file like this:
define('DS', DIRECTORY_SEPARATOR);
define('ROOT', dirname(__FILE__));
define('PAGES', ROOT.DS.'pages'.DS);
define('LAYOUTS', ROOT.DS.'layouts'.DS);
define('PHP', '.php');
$pageLayout = 'default';
if(empty($_GET['p'])) $page = 'home';
else $page = $_GET['p'];
if(file_exists(PAGES.$page.PHP)) {
$pageTitle = ucwords($page);
} else {
header("HTTP/1.0 404 Not Found");
$page = '404';
$pageTitle = '404 - Page Not Found';
}
ob_start();
include PAGES.$page.PHP;
$pageContent = ob_get_clean();
include LAYOUTS.$pageLayout.PHP;
You probably won't need to edit that at all unless you want to change a few default settings. Then create two folders, "layouts" and "pages".
In the layouts folder, create a default layout called "default.php". Something like this:
<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
<head>
<title><?=$pageTitle?> - Your Site</title>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
<meta name="keywords" content="" />
<meta name="description" content="" />
<link rel="shortcut icon" type="image/x-icon" href="/favicon.ico" />
<link rel="stylesheet" type="text/css" href="/style.css" />
<?=$pageScripts?>
</head>
<body>
<div id="page-wrap">
<ul id="navbar">
<li><a href="first-link">First Page</a></li>
<li><a href="second-link">Second Page</a></li>
</ul>
<div id="main-area">
<a id="logo" href="/"></a>
<div id="content-container">
<div id="content-body">
<?=$pageContent?>
</div>
</div>
</div>
<div id="footer">
<p>yoursite.com © <?=date('Y')?> | <a href="/privacy-policy">Privacy Policy</a></p>
</div>
</div>
</body>
</html>
Notice the usage of variables $pageContent, $pageScripts, and $pageTitle. You can set the $pageTitle and $pageScripts within the page. $pageContent is where your content will appear in the layout. There is also one more variable you can set, $pageLayout, which you can set to use a layout other than the default one.
Now your page URLs will look something like "yoursite.com/page" with no file extension. You shouldn't have to worry too much about evil users including bad files because they can only include stuff within the "pages" folder. You can also still access all your other files directly, by using the full URL with extension.
Oh, also make sure you have a file called "404.php" within the "pages" folder, or bad things might happen 
This is the file that will get called if no page could be found. It uses the layout too.
I think that's everything... so happy templating!
Resize images using this PHP script
Always bugs me when people stretch their images out of proportion, there's really no reason for it. Just use this simply function to nicely resize your images! If you want all your images the same size (like a square), I recommend "trim". Otherwise use "squeeze". If you can think of more appropriate fill names, let me know!
// @fill
// center - Centers the image without any scaling. May be smaller than dimensions, or cropped.
// stretch - Stretches the image to fill dimensions. May change image proportions.
// squeeze - Scales the image, maintaining original proportions. May not fill dimensions.
// trim - Scales the image, maintaining original proportions, to fill dimensions. Image may be centered and trimmed.
// trim_rand - Scales the image, maintaining original proportions, to fill dimensions. Trimmed randomly.
function resize($src_filename, $dst_filename, $dst_width, $dst_height, $fill='squeeze', $quality=80, $png_filters=PNG_NO_FILTER)
{
if(!file_exists($src_filename)) {
//throw new Exception("File does not exist: $src_filename");
return false;
}
if(empty($dst_filename)) {
$dst_filename = $src_filename;
}
if($dst_width <= 0) {
//throw new Exception("Width must be positive: $dst_width");
return false;
}
if($dst_height <= 0) {
//throw new Exception("Height must be positive: $dst_height");
return false;
}
$src_ext = substr($src_filename,strrpos($src_filename,'.')+1);
switch(strtolower($src_ext)) {
case 'gif':
$src_image = imagecreatefromgif($src_filename);
break;
case 'jpe':
case 'jpeg':
case 'jpg':
$src_image = imagecreatefromjpeg($src_filename);
break;
case 'png':
$src_image = imagecreatefrompng($src_filename);
break;
default:
//throw new Exception("Invalid source file extension: $src_ext");
return false;
}
$src_width = imagesx($src_image);
$src_height = imagesy($src_image);
switch(strtolower(trim($fill))) {
case 'center':
$src_x = round($src_width/2-$dst_width/2);
$src_y = round($src_height/2-$dst_height/2);
if($src_x < 0) {
$dst_width = $src_width;
$src_x = 0;
}
if($src_y < 0) {
$dst_height = $src_height;
$src_y = 0;
}
$dst_image = imagecreatetruecolor($dst_width, $dst_height);
imagecopyresampled($dst_image, $src_image, 0, 0, $src_x, $src_y, $dst_width, $dst_height, $dst_width, $dst_height);
break;
case 'stretch':
$dst_image = imagecreatetruecolor($dst_width, $dst_height);
imagecopyresampled($dst_image, $src_image, 0, 0, 0, 0, $dst_width, $dst_height, $src_width, $src_height);
break;
case 'crop':
case 'crop_center':
case 'trim_center':
case 'trim':
$src_ratio = $src_width/$src_height;
$dst_ratio = $dst_width/$dst_height;
if($src_ratio < $dst_ratio) // trim top and bottom
{
$ratio = $src_width/$dst_width;
$crop_height = $dst_height*$ratio;
$src_y = round(($src_height-$crop_height)/2);
$crop_width = $src_width;
$src_x = 0;
}
else // trim left and right
{
$ratio = $src_height/$dst_height;
$crop_width = $dst_width*$ratio;
$src_x = round(($src_width-$crop_width)/2);
$crop_height = $src_height;
$src_y = 0;
}
$dst_image = imagecreatetruecolor($dst_width, $dst_height);
imagecopyresampled($dst_image, $src_image, 0, 0, $src_x, $src_y, $dst_width, $dst_height, $crop_width, $crop_height);
break;
case 'crop_rand':
case 'trim_rand':
$src_ratio = $src_width/$src_height;
$dst_ratio = $dst_width/$dst_height;
if($src_ratio < $dst_ratio) // trim top and bottom
{
$ratio = $src_width/$dst_width;
$crop_height = $dst_height*$ratio;
$src_y = rand(0,$src_height-$crop_height);
$crop_width = $src_width;
$src_x = 0;
}
else // trim left and right
{
$ratio = $src_height/$dst_height;
$crop_width = $dst_width*$ratio;
$src_x = rand(0,$src_width-$crop_width);
$crop_height = $src_height;
$src_y = 0;
}
$dst_image = imagecreatetruecolor($dst_width, $dst_height);
imagecopyresampled($dst_image, $src_image, 0, 0, $src_x, $src_y, $dst_width, $dst_height, $crop_width, $crop_height);
break;
case 'squeeze':
case 'stretch_prop':
case 'fit':
$ratio = max($src_width/$dst_width, $src_height/$dst_height);
if($ratio < 1) $ratio = 1; // do not enlarge
$dst_width = round($src_width/$ratio);
$dst_height = round($src_height/$ratio);
$dst_image = imagecreatetruecolor($dst_width, $dst_height);
imagecopyresampled($dst_image, $src_image, 0, 0, 0, 0, $dst_width, $dst_height, $src_width, $src_height);
break;
default:
//throw new Exception("Unrecognized fill type: $fill");
return false;
}
$dst_ext = substr($dst_filename,strrpos($dst_filename,'.')+1);
if(empty($dst_ext)) {
$dst_ext = $src_ext;
$dst_filename .= ".$src_ext";
}
switch(strtolower($dst_ext)) {
case 'gif':
return imagegif($dst_image, $dst_filename);
case 'jpe':
case 'jpeg':
case 'jpg':
return imagejpeg($dst_image, $dst_filename, $quality);
case 'png':
return imagepng($dst_image, $dst_filename, $quality, $png_filters);
default:
//throw new Exception('Invalid destination file extension: $dst_ext');
return false;
}
}
?>
Use .htaccess to hide file extensions
Create a file at the root of your web server called ".htaccess". Put the following code inside:
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule .* $0.php
This will make it so you can access all your PHP pages without having to type the ".php" extension the URL or your <a href>s. i.e., you can access "yoursite.com/about.php" just by going to "yoursite.com/about". The actual file names should still have the .php extension though. You can do this with whatever file type you like too.
cPanel Quick Config – Quick Tip
Maybe I'm slow, but I just discovered "php.ini QuickConfig" in cPanel 11. It probably exists in prior versions too. It was hidden under "Software / Services". Most of the default settings should be fine, but you might want to disable register_globals if it isn't disabled already. This will prevent malicious visitors from setting your PHP variables themselves by attaching arguments to the URL. Just make sure you always use $_GET and $_POST where ever it's necessary.