private static Mat GetTargetMatFromScreen(int targetScreen, int targetAdapter = 0, Rectangle cropRegion = default)
{
    Mat mat = null; // Initialize mat
    using (Bitmap screenshot = GetDuplicationScreenshot(0, 0)) // Obtain screenshot of target display (via DesktopDuplication)
    {
        /// screenshot.Save("test.png"); // debug
        if (cropRegion != default) // Check if a cropRegion was provided
        {
            using (Bitmap croppedScreenshot = CropImage(screenshot, cropRegion)) // Crop screenshot based on cropRegion and store in croppedScreenshot
            {
                if (croppedScreenshot != null) // Check if croppedScreenshot is NOT null
                    mat = BitmapConverter.ToMat(croppedScreenshot); // Create Mat converted from croppedScreenshot
            }
        }
        else
        {
            mat = BitmapConverter.ToMat(screenshot); // Create Mat converted from screenshot Bitmap
            if (mat == null) // Check if mat is null
                Console.WriteLine("Could not create haystack Mat from screenshot. Image search canceled."); // Output info to log
        }
    }
    return mat; // Return mat
}

private static Mat GetTargetMatFromScreen(int targetScreen, int targetAdapter = 0, Rectangle cropRegion = default)
{
    Mat mat = null; // Initialize mat
    using (Bitmap screenshot = GetDuplicationScreenshot(0, 0)) // Obtain screenshot of target display (via DesktopDuplication)
    {
        /// screenshot.Save("test.png"); // debug
        if (cropRegion != default) // Check if a cropRegion was provided
        {
            using (Bitmap croppedScreenshot = CropImage(screenshot, cropRegion)) // Crop screenshot based on cropRegion and store in croppedScreenshot
            {
                if (croppedScreenshot != null) // Check if croppedScreenshot is NOT null
                    mat = BitmapConverter.ToMat(croppedScreenshot); // Create Mat converted from croppedScreenshot
            }
        }
        else
        {
            mat = BitmapConverter.ToMat(screenshot); // Create Mat converted from screenshot Bitmap
            if (mat == null) // Check if mat is null
                Console.WriteLine("Could not create haystack Mat from screenshot. Image search canceled."); // Output info to log
        }
    }
    return mat; // Return mat
}