public static void TransferPixels(Bitmap bitmap_dest,
TwainDotNet.TwainNative.ImageInfo imageInfo, TwainDotNet.TwainNative.ImageMemXfer memxfer_src)
{
switch (imageInfo.SamplesPerPixel)
{
case 1: // greyscale
switch (imageInfo.BitsPerPixel)
{
case 1:
case 8:
TransferPixelsGreyscale(bitmap_dest, imageInfo, memxfer_src);
break;
default:
throw new TwainException("unsupported bits per pixel: " + imageInfo.BitsPerPixel);
}
break;
case 3: // RGB
TransferPixelsRGB(bitmap_dest, imageInfo, memxfer_src);
break;
case 4: // CMYK
default:
throw new TwainException("Samples Per Pixel Unsupported: " + imageInfo.SamplesPerPixel.ToString());
}
}
private static void TransferPixelsGreyscale(Bitmap bitmap_dest,
TwainDotNet.TwainNative.ImageInfo imageInfo, TwainDotNet.TwainNative.ImageMemXfer memxfer_src)
{
BitmapInfoHeaderIndexedColor bitmapInfo = new BitmapInfoHeaderIndexedColor();
bitmapInfo.Width = (int)memxfer_src.Columns;
bitmapInfo.Height = -(int)memxfer_src.Rows;
// bitmapInfo.Size = sizeof(BitmapInfoHeader); // requires unsafe
bitmapInfo.Size = 40; // the size of the initial header, not including color table
bitmapInfo.Planes = 1;
bitmapInfo.SizeImage = 0;
bitmapInfo.BitCount = imageInfo.BitsPerPixel;
if (imageInfo.Planar == (short)TwainNative.TwainBool.True)
{
throw new TwainException("Planar format invalid for greyscale data.");
}
if (imageInfo.BitsPerPixel == 8)
{
BitmapInfoHeaderIndexedColor.setupGreyscaleIndices(ref bitmapInfo);
bitmapInfo.ClrUsed = 256;
}
else if (imageInfo.BitsPerPixel == 1)
{
BitmapInfoHeaderIndexedColor.setupBWIndices(ref bitmapInfo);
bitmapInfo.ClrUsed = 2;
}
else
{
throw new TwainException("TransferPixelsGreyscale() only supports 8 bits per pixel");
}
using (Graphics graphics = Graphics.FromImage(bitmap_dest))
{
IntPtr hdc = graphics.GetHdc();
try
{
Gdi32Native.SetDIBitsToDevice(
hdc,
(int)memxfer_src.XOffset,
(int)memxfer_src.YOffset,
(int)memxfer_src.Columns,
(int)memxfer_src.Rows,
0, 0, 0,
(int)memxfer_src.Rows,
memxfer_src.Memory.TheMem,
bitmapInfo,
0);
}
finally
{
graphics.ReleaseHdc(hdc);
}
}
}
public static Bitmap NewBitmapForImageInfo(TwainDotNet.TwainNative.ImageInfo imageInfo)
{
var bitmap = new Bitmap(imageInfo.ImageWidth, imageInfo.ImageLength, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
using (Graphics graphics = Graphics.FromImage(bitmap)) {
graphics.Clear(Color.White);
}
return(bitmap);
}
private static void TransferPixelsRGB(
Bitmap bitmap_dest,
TwainDotNet.TwainNative.ImageInfo imageInfo,
TwainDotNet.TwainNative.ImageMemXfer memxfer_src)
{
BitmapInfoHeader bitmapInfo = new BitmapInfoHeader();
bitmapInfo.Width = (int)memxfer_src.Columns;
bitmapInfo.Height = -(int)memxfer_src.Rows; // If biHeight is negative, the bitmap is a top-down DIB and its origin is the upper-left corner.
// bitmapInfo.Size = sizeof(BitmapInfoHeader); // requires unsafe
bitmapInfo.Size = 40;
bitmapInfo.Planes = 1;
bitmapInfo.SizeImage = (int)memxfer_src.Memory.Length;
bitmapInfo.ClrUsed = 0; // we are not using the indexed color table
bitmapInfo.Compression = 0; //BI_RGB An uncompressed format.
bitmapInfo.ClrImportant = 0; //If this value is zero, all colors are required.
if (imageInfo.Planar == (short)TwainNative.TwainBool.True)
{
// this means the data is in the buffer as RRRR-GGGGG-BBBB instead of RGB-RGB-RGB
// we don't currently support this decoding
throw new TwainException("Planar image format Unsupported.");
}
// imageInfo.BitsPerPixel can be (1, 8, 24, 40) - Twain Spec page (8-39)
// "The number of bits in each image pixel (or bit depth). This value is invariant across the
// image. 24 - bit R - G - B has BitsPerPixel = 24. 40 - bit C - M - Y - K has BitsPerPixel = 40.
// 8 - bit Grayscale has BitsPerPixel = 8.Black and White has BitsPerPixel = 1."
switch (imageInfo.BitsPerPixel)
{
case 24:
bitmapInfo.BitCount = imageInfo.BitsPerPixel;
break;
case 1: // imageInfo is 1bit B&W, should be in TransferPixelsGreyscale()
case 8: // imageInfo is 8bit grayscale, should be in TransferPixelsGreyscale()
case 40: // imageInfo is 40bit CMYL. DIBitmap only supports up to 32bits per pixel RGB.
default:
throw new TwainException("TransferPixelsRGB: unhandled image bit depth: " + imageInfo.BitsPerPixel.ToString());
}
//IntPtr scan0 = new IntPtr(memxfer_src.Memory.TheMem.ToInt32() + 40);
//Bitmap bitmap = new Bitmap(bitmapInfo.Width, bitmapInfo.Height, bitmapInfo.Width * 3, System.Drawing.Imaging.PixelFormat.Format24bppRgb, scan0);
using (Graphics graphics = Graphics.FromImage(bitmap_dest))
{
IntPtr hdc = graphics.GetHdc();
try
{
Gdi32Native.SetDIBitsToDevice(
hdc,
(int)memxfer_src.XOffset,
(int)memxfer_src.YOffset,
(int)memxfer_src.Columns,
(int)memxfer_src.Rows,
0, 0, 0,
(int)memxfer_src.Rows,
memxfer_src.Memory.TheMem,
bitmapInfo,
0);
}
finally
{
graphics.ReleaseHdc(hdc);
}
}
}
