XamarinTest.cs

public void RunThisOnYourDevice()
{
    string inputImagesRoot = "YourRootToImages"; // https://github.com/SixLabors/ImageSharp/tree/master/tests/Images/Input
    string reportFile = Path.Combine("WhateverPathYouCanWriteTo", "Report.txt");

    string[] files = Directory.EnumerateFiles(
            inputImagesRoot,
            "*.*",
            SearchOption.AllDirectories).Where(
            f => Path.GetExtension(f).ToLower() == ".png" || Path.GetExtension(f).ToLower() == ".jpg"
                                                          || Path.GetExtension(f).ToLower() == ".jpeg"
                                                          || Path.GetExtension(f).ToLower() == ".bmp"
                                                          || Path.GetExtension(f).ToLower() == ".gif")
        .ToArray();
    using (var report = new StreamWriter(reportFile))
    {
        foreach (string file in files)
        {
            report.WriteLine($"*** Testing {file} ...");

            try
            {
                using (var img = Image.Load(file, out IImageFormat format))
                {
                }

                report.WriteLine("   ... SUCCESS!");
            }
            catch (NotSupportedException)
            {
                report.WriteLine($"  ... NotSupportedException (invalid input)");
            }
            catch (ImageFormatException)
            {
                report.WriteLine($"  ... ImageFormatException (invalid input)");
            }
            catch (Exception ex)
            {
                report.WriteLine($"!!! FAILED: {ex.GetType().Name} : {ex.Message}");
                report.WriteLine(ex.StackTrace);
            }


            ms.Seek(0, SeekOrigin.Begin);
        }
    }
}