private void snapshotPicbox_SizeChanged(object sender, EventArgs e)
{
if (snapshotPicbox.Width <= snapshotPicbox.Image.Width ||
snapshotPicbox.Height <= snapshotPicbox.Image.Height)
snapshotPicbox.SizeMode = PictureBoxSizeMode.Zoom;
else
snapshotPicbox.SizeMode = PictureBoxSizeMode.CenterImage;
}