コード例 #1
0
        /// <summary>
        /// Gets the number of the overlay frame that is applicable to a given image frame, if any.
        /// </summary>
        /// <remarks>
        /// <para>
        /// The DICOM Standard 2008, Part 3, Section C.9.3.1.1 states:
        /// "The frames within a Multi-frame Overlay shall be conveyed as a logical sequence. If Multi-frame
        /// Overlays are related to a Multi-frame Image, the order of the Overlay Frames are one to one with
        /// the order of the Image frames. Otherwise, no attribute is used to indicate the sequencing of the
        /// Overlay Frames. If Image Frame Origin (60xx,0051) is present, the Overlay frames are applied
        /// one to one to the Image frames, beginning at the indicated frame number. Otherwise, no attribute
        /// is used to indicated the sequencing of the Overlay Frames."
        /// </para>
        /// <para>
        /// This is taken to mean that each image frame may have at most ONE overlay frame from any given
        /// overlay plane group. The algorithm used here evaluates a number of conditions and computes an
        /// appropriate overlay frame number, if any. The cases are, in order of precedence:
        /// </para>
        /// <list>
        /// <item>If the overlay is embedded in the pixel data, this function always returns the same frame number
        /// as this was required under the 2004 version of the standard (the last version to allow this usage).</item>
        /// <item>If the overlay is not multi-frame, all image frames will match with the sole overlay frame.</item>
        /// <item>If the image frame number is less than <see cref="ImageFrameOrigin"/> or greater than
        /// <see cref="ImageFrameOrigin"/>+<see cref="NumberOfFramesInOverlay"/>-1, it will have no overlay frame.</item>
        /// <item>Otherwise, this function returns the matching overlay frame number as determined by the
        /// <see cref="ImageFrameOrigin"/>.</item>
        /// </list>
        /// <para>
        /// N.B.: This function does NOT access attributes outside this module (i.e. Number of Frames (0028,0008))
        /// so as to prevent unintended side effects in the dataset. Therefore, this information must be provided
        /// by the calling code via <paramref cref="totalImageFrames"/>.
        /// </para>
        /// </remarks>
        /// <param name="imageFrameNumber">The one-based image frame number.</param>
        /// <param name="totalImageFrames">The total number of frames in the image.</param>
        /// <returns>The one-based overlay frame number if an overlay frame exists for the given image frame; NULL otherwise.</returns>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if <paramref name="imageFrameNumber"/> does not specify a valid frame number according to <paramref name="totalImageFrames"/>.</exception>
        public int?GetRelevantOverlayFrame(int imageFrameNumber, int totalImageFrames)
        {
            // if image frame identification is invalid, fail
            if (imageFrameNumber < 1 || imageFrameNumber > totalImageFrames)
            {
                throw new ArgumentOutOfRangeException("imageFrameNumber", "imageFrameNumber must be a positive, non-zero value and less than or equal to totalImageFrames.");
            }

            // if the overlay plane is embedded in the pixel data, the overlay frames are required to be 1-to-1 with each image frame
            if (!HasOverlayData)
            {
                return(imageFrameNumber);
            }

            // if the overlay is not a multi-frame, then the only overlay frame is applicable to all image frames
            if (!IsMultiFrame)
            {
                return(1);
            }

            var origin = ImageFrameOrigin.GetValueOrDefault(1);
            var count  = NumberOfFramesInOverlay.GetValueOrDefault(1);

            // otherwise the origin and count specify the range of image frames for which a 1-to-1 relation exists to the overlay frames
            if (imageFrameNumber >= origin && imageFrameNumber < origin + count)
            {
                return(imageFrameNumber - (origin - 1));
            }

            return(null);
        }
コード例 #2
0
 /// <summary>
 /// Gets a value indicating whether or not this multi-frame overlay plane is valid given the total number of frames in the image.
 /// </summary>
 /// <remarks>
 /// DICOM 2009 PS 3.3 Section C.9.3.1.1 states that &quot;The Number of Frames in Overlay (60xx,0015) plus the Image Frame Origin (60xx,0051) minus 1
 /// shall be less than or equal to the total number of frames in the Multi-frame Image.&quot;
 /// </remarks>
 /// <param name="totalImageFrames">The total number of frames in the image.</param>
 /// <returns>True if this multi-frame overlay plane is valid or the overlay plane is not a multi-frame; False otherwise.</returns>
 public bool IsValidMultiFrameOverlay(int totalImageFrames)
 {
     if (totalImageFrames < 1)
     {
         throw new ArgumentOutOfRangeException("totalImageFrames", "Total number of frames in the image must be 1 or greater.");
     }
     return(NumberOfFramesInOverlay.GetValueOrDefault(1) + ImageFrameOrigin.GetValueOrDefault(1) - 1 <= totalImageFrames);
 }