title: Read a tiff file's dimension and resolution without loading it first
body: <p>How to read a tiff file's dimension (width and height) and resolution (horizontal and vertical) without first loading it into memory by using code like the following.  It is too slow for big files and I don't need to manipulate them.</p>
  
  <pre><code>Image tif = Image.FromFile(@"C:\large_size.tif");
  float width = tif.PhysicalDimension.Width;
  float height = tif.PhysicalDimension.Height;
  float hresolution = tif.HorizontalResolution;
  float vresolution = tif.VerticalResolution;
  tif.Dispose();
  </code></pre>
  
  <p>Edit:</p>
  
  <p>Those tiff files are Bilevel and have a dimension of 30x42 inch.  The file sizes are about 1~2 MB.  So the method above works Ok but slow.</p>