Exemple #1
0
        /// <summary>
        /// Decompress a JPEG image to an RGB, grayscale, or CMYK image.
        /// </summary>
        /// <param name="jpegBuf">Pointer to a buffer containing the JPEG image to decompress. This buffer is not modified.</param>
        /// <param name="jpegBufSize">Size of the JPEG image (in bytes).</param>
        /// <param name="outBuf">The buffer into which to store the decompressed JPEG image.</param>
        /// <param name="outBufSize">Size of <paramref name="outBuf"/> (in bytes).</param>
        /// <param name="destPixelFormat">Pixel format of the destination image (see <see cref="PixelFormat"/> "Pixel formats".)</param>
        /// <param name="flags">The bitwise OR of one or more of the <see cref="TJFlags"/> "flags".</param>
        /// <param name="width">Width of image in pixels.</param>
        /// <param name="height">Height of image in pixels.</param>
        /// <param name="stride">Bytes per line in the destination image.</param>
        public unsafe void Decompress(IntPtr jpegBuf, ulong jpegBufSize, IntPtr outBuf, int outBufSize, TJPixelFormat destPixelFormat, TJFlags flags, out int width, out int height, out int stride)
        {
            if (this.isDisposed)
            {
                throw new ObjectDisposedException("this");
            }

            int subsampl;
            int colorspace;
            var funcResult = TurboJpegImport.TjDecompressHeader(
                this.decompressorHandle,
                jpegBuf,
                jpegBufSize,
                out width,
                out height,
                out subsampl,
                out colorspace);

            if (funcResult == -1)
            {
                TJUtils.GetErrorAndThrow();
            }

            var targetFormat = destPixelFormat;

            stride = TurboJpegImport.TJPAD(width * TurboJpegImport.PixelSizes[targetFormat]);
            var bufSize = stride * height;

            if (outBufSize < bufSize)
            {
                throw new ArgumentOutOfRangeException(nameof(outBufSize));
            }

            funcResult = TurboJpegImport.TjDecompress(
                this.decompressorHandle,
                jpegBuf,
                jpegBufSize,
                outBuf,
                width,
                stride,
                height,
                (int)targetFormat,
                (int)flags);

            if (funcResult == -1)
            {
                TJUtils.GetErrorAndThrow();
            }
        }