getDeviceNToRGBBitmap
Convert a DeviceN image to a raw RGB bitmap.
getDeviceNToRGBBitmap([out] int *width, [out] int *height, [out] int *stride, [out, retval] HGLOBAL *data)
This function converts the DeviceN bitmap generated by the last call
to
convertPageToDeviceNImage to RGB, and returns a raw bitmap. It
is identical to getDeviceNToRGBPicture, except that it returns a
raw bitmap instead of an OLE IPicture object.
The image will be returned as a 24-bit RGB bitmap.
By default, this function will return the same thing as
convertPageToBitmap2 in imageDevNToRGB mode. The
difference is that individual color channels can be removed with
removeDeviceNChannel.
width, height, and stride are
output arguments that provide the bitmap width, height, and stride
(bytes per row).
NB: The returned value is an HGLOBAL (i.e.,
XpdfRasterizer allocates it with GlobalAlloc), and the
caller is responsible for calling GlobalFree
(or Marshal.FreeHGBlobal) to free it.
C#:
rast.convertPageToDeviceNImage(page, dpi);
int nChannels = rast.getNumDeviceNChannels();
for (int i = 0; i < nChannels; ++i) {
string channelName = rast.getDeviceNChannelName(i);
if (....) {
rast.removeDeviceNChannel(i);
}
}
int width, height, stride;
IntPtr bitmapData = rast.getDeviceNToRGBBitmap(out width, out height, out stride);
Bitmap bmp = new Bitmap(width, height, stride, PixelFormat.Format24bppRgb, bitmapData);
// ... use bmp ...
Marshal.FreeHGlobal(bitmapData);
rast.clearDeviceNImage()