pdfWriteDeviceNToRGBBitmap
Convert a DeviceN image to RGB and write to an image file.
int pdfWriteDeviceNToRGBBitmap(PDFHandle pdf, int format, char *fileName)
This function converts the DeviceN bitmap generated by the last call
to
pdfConvertPageToDeviceNImage to RGB, and then writes it to an
image file.
This function is very similar to pdfGetDeviceNToRGBBitmap, except
that it writes the image to disk, rather then returning an in-memory
bitmap.
The format and fileName arguments are the
same as for pdfWritePageBitmap.
By default, this function will generate the same image as
pdfWritePageBitmap in pdfImageDevNToRGB mode.
The difference is that individual color channels can be removed with
pdfRemoveDeviceNChannel.
C:
int nChannels, i;
char *channelName;
unsigned int channelCMYK;
PDFImageHeader hdr;
char *bits;
int err;
err = pdfConvertPageToDeviceNImage(pdf, pageNum, dpi);
if (err != pdfOk) {
/* handle the error */
...
}
nChannels = pdfGetNumDeviceNChannels(pdf);
for (i = 0; i < nChannels; ++i) {
channelName = pdfGetDeviceNChannelName(pdf, i);
if ( ... ) {
pdfRemoveDeviceNChannel(pdf, i);
}
}
pdfWriteDeviceNToRGBBitmap(pdf, pdfImageFilePNG, "out.png");
/* free the internal storage used by pdfConvertPageToDeviceNImage */
pdfClearDeviceNImage(pdf);