How to adjust this script to use Glob instead of 1 file - php

Question

I have created this script based on reading other posts on StackOverflow. The script creates a thumbnail from the original image and adds it to a folder. The source images are located on my local server so Glob would work however I am not sure how to adjust this script so that it will run this function on all files in a folder (Glob). I realize it may be memory intensive but I only need to do it a few times on several folders and I'll be done with it.
Just in case you are questioning the reason I have included $height2, it is a little hack I came up with where we create the thumbnail while maintaining the aspect ratio then only save the top 250px so that the thumb is 250 x 250 but not distorted (stretched). It works great.
I just need to adjust to do a batch of all images in the source folder.
Any help would be great. Please keep in mind that I am a front end developer (html and css) and not great at PHP. This script alone took me forever to make work lol.
If anyone can help me adjust it for a full folder, that would be great.
foreach(glob('SourceFolder/*.jpg', GLOB_NOSORT) as $url); {
Thumbnail ($url, "DestinationFolder/*.jpg");
function Thumbnail($url, $filename, $width = 250, $height = true, $height2 = 250) {
// download and create gd image
$image = ImageCreateFromString(file_get_contents($url));
// calculate resized ratio
// Note: if $height is set to TRUE then we automatically calculate the height based on the ratio
$height = $height === true ? (ImageSY($image) * $width / ImageSX($image)) : $height;
// create image
$output = ImageCreateTrueColor($width, $height2);
ImageCopyResampled($output, $image, 0, 0, 0, 0, $width, $height, ImageSX($image), ImageSY($image));
// save image
ImageJPEG($output, $filename, 100);
}
}

Answer 1

I was able to adjust the code on my own after reading the online PHP manual.
The final code:
foreach (glob("SourceFolder/*.jpg") as $url) {
$destdir = "Destination/" . basename($url, null);
$width = 250;
$height = true;
// download and create gd image
$image = ImageCreateFromString(file_get_contents($url));
// calculate resized ratio
// Note: if $height is set to TRUE then we automatically calculate the height based on the ratio
$height = $height === true ? (ImageSY($image) * $width / ImageSX($image)) : $height;
// create image
$output = ImageCreateTrueColor($width, $height);
ImageCopyResampled($output, $image, 0, 0, 0, 0, $width, $height, ImageSX($image), ImageSY($image));
// save image
ImageJPEG($output, $destdir, 100);
}

Answer 2

This solution uses opendir and readdir. I have found that this approach can
handle folders with more files.
// Set desired height and width
$desiredWidth = 250;
$desiredHeight = true;
// Set source and destination folders
$srcFolder = "SourceFolder";
$destFolder = "Destination";
// This is more memory efficient than using glob()
$dh = opendir($srcFolder);
if ( ! $dh ) {
die('Unable to open folder ' . $srcFolder);
}
while($filename = readdir($dh) ) {
// only process jpg files.
if ( preg_match('/.jpg$/', $filename) ) {
$inputFile = sprintf('%s/%s', $srcFolder, $filename);
$outputFile = sprintf('%s/%s', $destFolder, $filename);
echo "file: $filename\n";
echo "input: $inputFile\n";
echo "output: $outputFile\n";
$inputImage = #ImageCreateFromJpeg($inputFile);
if ( $inputImage ) {
// calculate resized ratio
// Note: if $height is set to TRUE then we automatically calculate the height based on the ratio
$height = $desiredHeight === true ? (ImageSY($inputImage) * $desiredWidth / ImageSX($inputImage)) : $desiredHeight;
// create image
$outputImage = ImageCreateTrueColor($desiredWidth, $height);
ImageCopyResampled($outputImage, $inputImage, 0, 0, 0, 0, $desiredWidth, $height, ImageSX($inputImage), ImageSY($inputImage));
// save image
ImageJPEG($outputImage, $outputFile, 100);
ImageDestroy($inputImage);
ImageDestroy($outputImage);
} else {
echo "Could not process file\n";
}
}
}
closedir($dh);