invisio v2.0

<?php
if (isset($_POST['image'])) {
    // $data = $_POST['image'];
    // $data = str_replace('data:image/png;base64,', '', $data);
    // $data = str_replace(' ', '+', $data);
    // $decodedData = base64_decode($data);

// Retrieve base64-encoded image data from POST request
    $base64ImageData = $_POST['image'];
    
    // Remove the data prefix (e.g., "data:image/png;base64,")
    list(, $base64ImageData) = explode(';', $base64ImageData);
    list(, $base64ImageData) = explode(',', $base64ImageData);
    
    // Decode base64 data
    $decodedImageData = base64_decode($base64ImageData);
    
    // Create an image resource from the decoded data
    $image = imagecreatefromstring($decodedImageData);
    
    // Get the dimensions of the image
    $width = imagesx($image);
    $height = imagesy($image);
    
    // Create a new true-color image with a transparent background
    $outputImage = imagecreatetruecolor($width, $height);
    $transparentColor = imagecolorallocatealpha($outputImage, 0, 0, 0, 127);
    imagefill($outputImage, 0, 0, $transparentColor);
    imagesavealpha($outputImage, true);
    
    // Set the color of the background to be removed (white in this case)
    $whiteColor = imagecolorallocate($image, 255, 255, 255);
    
    // Loop through each pixel in the input image
    for ($x = 0; $x < $width; $x++) {
        for ($y = 0; $y < $height; $y++) {
            $pixelColor = imagecolorat($image, $x, $y);
    
            // If the pixel color is not white, copy it to the output image
            if ($pixelColor !== $whiteColor) {
                imagesetpixel($outputImage, $x, $y, $pixelColor);
            }
        }
    }
    
    // Set the path to your output PNG file
    $outputFile = 'upload/join/signature/output.png';
    // Save the resulting image to the output file
    imagepng($outputImage, $outputFile);
    
    // Free up memory by destroying the image resources
    imagedestroy($image);
    imagedestroy($outputImage);
    
    echo 'Background removed and image saved successfully!';

} else {
    echo 'Error: No signature data received.';
}