await Task.WhenAll(images.Select(image => Task.Run(async() =>
{
if (image.HasAlpha)
{
var tasks = new Task[2];
var pixels = image.GetPixels();
IPixel <byte>?firstPixelX = null;
IPixel <byte>?lastPixelX = null;
IPixel <byte>?firstPixelY = null;
IPixel <byte>?lastPixelY = null;
foreach (var pixel in pixels)
{
if (pixel.GetChannel(3) != 255)
{
for (var i = 0; i < pixel.Channels; i++)
{
pixel.SetChannel(i, 0);
}
}
}
tasks[0] = Task.Run(() =>
{
for (var i = 0; i < image.Width; i++)
{
var targetPixel = pixels.GetPixel(i, image.Height / 2);
if (targetPixel.GetChannel(3) == 255 && (i == 0 || pixels.GetPixel(i - 1, image.Height / 2).GetChannel(3) == 0))
{
firstPixelX = targetPixel;
}
else if (targetPixel.GetChannel(3) == 255 && (i == image.Width - 1 || pixels.GetPixel(i + 1, image.Height / 2).GetChannel(3) == 0))
{
lastPixelX = targetPixel;
}
}
});
tasks[1] = Task.Run(() =>
{
for (var i = 0; i < image.Height; i++)
{
var targetPixel = pixels.GetPixel(image.Width / 2, i);
if (targetPixel.GetChannel(3) == 255 && (i == 0 || pixels.GetPixel(image.Width / 2, i - 1).GetChannel(3) == 0))
{
firstPixelY = targetPixel;
}
else if (targetPixel.GetChannel(3) == 255 && (i == image.Height - 1 || pixels.GetPixel(image.Width / 2, i + 1).GetChannel(3) == 0))
{
lastPixelY = targetPixel;
}
}
});
await Task.WhenAll(tasks);
if (firstPixelX != null && lastPixelX != null && firstPixelY != null && lastPixelY != null)
{
image.Crop(new MagickGeometry(firstPixelX.X, firstPixelY.Y, lastPixelX.X - firstPixelX.X, lastPixelY.Y - firstPixelY.Y));
image.RePage();
}
}
progressReporter?.Report(1);
return(image);
})));
await Task.WhenAll(images.Select(image => Task.Run(() =>
{
if (arguments == null || !arguments.Any(arg => arg.name == "percentage" && arg.value != null) || !ushort.TryParse(arguments.Single(arg => arg.name == "percentage").value, out var percentage))