Increases the size of each pixel within an image

pixel-enlarger.php

<?php

// Validate file input
$file = $argv[1] ?? "";
if($file === ""){
	echo "Please provide an image" . PHP_EOL;
	
	return;
}
if(substr($file, -4) !== ".png"){
	echo "This file is not a image" . PHP_EOL;
	
	return;
}
if(!file_exists($file)){
	echo "Image not found" . PHP_EOL;
	
	return;
}

// Validate scale input
$scale = (int)$argv[2] ?? 0;
if($scale < 2){
	echo "Scale must be greater than 1" . PHP_EOL;
	
	return;
}

$image = imagecreatefrompng($file); // Create image from input
[$width, $height] = getimagesize($file); // Get input image width & height

$newImage = imagecreatetruecolor($width * $scale, $height * $scale); // Create a new image, $scale times bigger than the input image

$xOffset = $yOffset = 0; // Define offset variables

// Loop through every pixel in the X axis in the input image
for($x = 0; $x < $width; ++$x){
	// Loop through every pixel in the Y axis in the input image
	for($y = 0; $y < $height; ++$y){
		imagesetpixel($newImage, ($x + $xOffset), ($y + $yOffset), imagecolorat($image, $x, $y)); // Set the original pixel
		for($xi = 0; $xi < $scale; ++$xi){
			for($yi = 0; $yi < $scale; ++$yi){
				imagesetpixel($newImage, ($x + $xOffset) + $xi, ($y + $yOffset) + $yi, imagecolorat($image, $x, $y)); // Set the pixel at +($xi, $yi)
			}
		}
		
		$yOffset += $scale - 1; // Increase Y offset
	}
	$yOffset = 0; // Reset Y offset
	$xOffset += $scale - 1; // Increase X offset
}

imagepng($newImage, substr($file, 0, -4) . "-enlarged.png"); // Create the enlarged image
// Destroy images after completion
imagedestroy($image);
imagedestroy($newImage);