/// <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="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="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 static unsafe Span <byte> Compress(this TJCompressor @this, ReadOnlySpan <byte> srcBuf, Span <byte> destBuf, int stride, int width, int height, PixelFormat pixelFormat, TJSubsamplingOption subSamp, int quality, TJFlags flags)
{
_ = @this ?? throw new ArgumentNullException(nameof(@this));
var tjPixelFormat = TJGdiPlusUtils.ConvertPixelFormat(pixelFormat);
return(@this.Compress(srcBuf, destBuf, stride, width, height, tjPixelFormat, subSamp, quality, flags));
}
/// <summary>
/// Compresses input image to the jpeg format with specified quality.
/// </summary>
/// <param name="srcPtr">
/// Pointer to an 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 static byte[] Compress(this TJCompressor @this, IntPtr srcPtr, int stride, int width, int height, PixelFormat pixelFormat,
TJSubsamplingOption subSamp, int quality, TJFlags flags)
{
_ = @this ?? throw new ArgumentNullException(nameof(@this));
var tjPixelFormat = TJGdiPlusUtils.ConvertPixelFormat(pixelFormat);
return(@this.Compress(srcPtr, stride, width, height, tjPixelFormat, subSamp, quality, flags));
}
/// <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="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>
/// <returns>Decompressed image of specified format.</returns>
/// <exception cref="TJException">Throws if underlying decompress function failed.</exception>
/// <exception cref="ObjectDisposedException">Object is disposed and can not be used anymore.</exception>
/// <exception cref="NotSupportedException">Convertion to the requested pixel format can not be performed.</exception>
public static unsafe Bitmap Decompress(this TJDecompressor @this, IntPtr jpegBuf, ulong jpegBufSize, PixelFormat destPixelFormat, TJFlags flags)
{
var targetFormat = TJGdiPlusUtils.ConvertPixelFormat(destPixelFormat);
int width;
int height;
int stride;
var buffer = @this.Decompress(jpegBuf, jpegBufSize, targetFormat, flags, out width, out height, out stride);
Bitmap result;
fixed(byte *bufferPtr = buffer)
{
result = new Bitmap(width, height, stride, destPixelFormat, (IntPtr)bufferPtr);
if (destPixelFormat == PixelFormat.Format8bppIndexed)
{
result.Palette = TJGdiPlusUtils.FixPaletteToGrayscale(result.Palette);
}
}
return(result);
}
