 for the possible values, see <a href="API-datastruct.html#LibRaw_thumbnail_formats">description
        of constants and data structures</a>.</p>
    <p>The function returns an integer number in accordance with the <a href="API-notes.html#errors">return
        code convention</a>: positive if any system call has returned an error,
      negative (from the <a href="API-datastruct.html#LibRaw_errors">LibRaw
        error list</a>) if there has been an error situation within LibRaw.</p>
    <h3></h3>
    <p>