/// <summary>
/// Compresses input image to the jpeg format with specified quality.
/// </summary>
/// <param name="srcBuf">
/// Image buffer containing RGB, grayscale, or CMYK pixels to be compressed.
/// This buffer is not modified.
/// </param>
/// <param name="stride">
/// Bytes per line in the source image.
/// Normally, this should be <c>width * BytesPerPixel</c> if the image is unpadded,
/// or <c>TJPAD(width * BytesPerPixel</c> if each line of the image
/// is padded to the nearest 32-bit boundary, as is the case for Windows bitmaps.
/// You can also be clever and use this parameter to skip lines, etc.
/// Setting this parameter to 0 is the equivalent of setting it to
/// <c>width * BytesPerPixel</c>.
/// </param>
/// <param name="width">Width (in pixels) of the source image.</param>
/// <param name="height">Height (in pixels) of the source image.</param>
/// <param name="pixelFormat">Pixel format of the source image (see <see cref="PixelFormat"/> "Pixel formats").</param>
/// <param name="subSamp">
/// The level of chrominance subsampling to be used when
/// generating the JPEG image (see <see cref="TJSubsamplingOption"/> "Chrominance subsampling options".)
/// </param>
/// <param name="quality">The image quality of the generated JPEG image (1 = worst, 100 = best).</param>
/// <param name="flags">The bitwise OR of one or more of the <see cref="TJFlags"/> "flags".</param>
/// <returns>
/// A <see cref="byte"/> array containing the compressed image.
/// </returns>
/// <exception cref="TJException">
/// Throws if compress function failed.
/// </exception>
/// <exception cref="ObjectDisposedException">Object is disposed and can not be used anymore.</exception>
/// <exception cref="NotSupportedException">
/// Some parameters' values are incompatible:
/// <list type="bullet">
/// <item><description>Subsampling not equals to <see cref="TJSubsamplingOption.Gray"/> and pixel format <see cref="TJPixelFormat.Gray"/></description></item>
/// </list>
/// </exception>
public unsafe byte[] Compress(byte[] srcBuf, int stride, int width, int height, TJPixelFormat tjPixelFormat, TJSubsamplingOption subSamp, int quality, TJFlags flags)
{
if (this.isDisposed)
{
throw new ObjectDisposedException("this");
}
CheckOptionsCompatibilityAndThrow(subSamp, tjPixelFormat);
var buf = IntPtr.Zero;
ulong bufSize = 0;
try
{
fixed(byte *srcBufPtr = srcBuf)
{
var result = TurboJpegImport.TjCompress2(
this.compressorHandle,
(IntPtr)srcBufPtr,
width,
stride,
height,
(int)tjPixelFormat,
ref buf,
ref bufSize,
(int)subSamp,
quality,
(int)flags);
if (result == -1)
{
TJUtils.GetErrorAndThrow();
}
}
var jpegBuf = new byte[bufSize];
Marshal.Copy(buf, jpegBuf, 0, (int)bufSize);
return(jpegBuf);
}
finally
{
TurboJpegImport.TjFree(buf);
}
}
/// <summary>
/// Compresses input image to the jpeg format with specified quality.
/// </summary>
/// <param name="srcBuf">
/// Image buffer containing RGB, grayscale, or CMYK pixels to be compressed.
/// This buffer is not modified.
/// </param>
/// <param name="destBuf">
/// A <see cref="byte"/> array containing the compressed image.
/// </param>
/// <param name="stride">
/// Bytes per line in the source image.
/// Normally, this should be <c>width * BytesPerPixel</c> if the image is unpadded,
/// or <c>TJPAD(width * BytesPerPixel</c> if each line of the image
/// is padded to the nearest 32-bit boundary, as is the case for Windows bitmaps.
/// You can also be clever and use this parameter to skip lines, etc.
/// Setting this parameter to 0 is the equivalent of setting it to
/// <c>width * BytesPerPixel</c>.
/// </param>
/// <param name="width">Width (in pixels) of the source image.</param>
/// <param name="height">Height (in pixels) of the source image.</param>
/// <param name="pixelFormat">Pixel format of the source image (see <see cref="TJPixelFormat"/> "Pixel formats").</param>
/// <param name="subSamp">
/// The level of chrominance subsampling to be used when
/// generating the JPEG image (see <see cref="TJSubsamplingOption"/> "Chrominance subsampling options".)
/// </param>
/// <param name="quality">The image quality of the generated JPEG image (1 = worst, 100 = best).</param>
/// <param name="flags">The bitwise OR of one or more of the <see cref="TJFlags"/> "flags".</param>
/// <returns>
/// A <see cref="Span{T}"/> which is a slice of <paramref name="destBuf"/> which holds the compressed image.
/// </returns>
/// <exception cref="TJException">
/// Throws if compress function failed.
/// </exception>
/// <exception cref="ObjectDisposedException">Object is disposed and can not be used anymore.</exception>
/// <exception cref="NotSupportedException">
/// Some parameters' values are incompatible:
/// <list type="bullet">
/// <item><description>Subsampling not equals to <see cref="TJSubsamplingOption.Gray"/> and pixel format <see cref="TJPixelFormat.Gray"/></description></item>
/// </list>
/// </exception>
public unsafe Span <byte> Compress(ReadOnlySpan <byte> srcBuf, Span <byte> destBuf, int stride, int width, int height, TJPixelFormat pixelFormat, TJSubsamplingOption subSamp, int quality, TJFlags flags)
{
if (this.isDisposed)
{
throw new ObjectDisposedException(nameof(TJCompressor));
}
CheckOptionsCompatibilityAndThrow(subSamp, pixelFormat);
ulong destBufSize = (ulong)destBuf.Length;
fixed(byte *srcBufPtr = srcBuf)
fixed(byte *destBufPtr = destBuf)
{
IntPtr destBufPtr2 = (IntPtr)destBufPtr;
var result = TurboJpegImport.TjCompress2(
this.compressorHandle,
(IntPtr)srcBufPtr,
width,
stride,
height,
(int)pixelFormat,
ref destBufPtr2,
ref destBufSize,
(int)subSamp,
quality,
(int)flags);
if (result == -1)
{
TJUtils.GetErrorAndThrow();
}
}
return(destBuf.Slice(0, (int)destBufSize));
}