pdfGetDeviceNToRGBBitmap
Convert a DeviceN image to RGB.
int pdfGetDeviceNToRGBBitmap(PDFHandle pdf, int rowPad, PDFImageHeader *imgHdr, char **bits)
This function converts the DeviceN bitmap generated by the last call
to
pdfConvertPageToDeviceNImage to RGB.
The bitmap will be a 24-bit RGB bitmap, handled in the
same way as for pdfConvertPageToBitmap2
in pdfImageRGB mode:
rowPad= each row will be padded out to a multiple of this number of bytes (typically 1 for no padding, or 4 to pad to a 32-bit boundary)imgHdr= a struct describing the output bitmap, with the following fields:width= image widthheight= image heightcolor=pdfImageDevNToRGB
bits= pointer to the returned bitmap data
pdfConvertPageToBitmap2 in pdfImageDevNToRGB mode.
The difference is that individual color channels can be removed with
pdfRemoveDeviceNChannel.
The caller is responsible for freeing the bits pointer
after using it, by calling pdfFreeMemory.
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);
}
}
pdfGetDeviceNToRGBBitmap(pdf, 4, &hdr, &bits);
... use the bitmap ...
/* the bitmap memory must be freed when you are finished */
pdfFreeMemory(bits);
/* free the internal storage used by pdfConvertPageToDeviceNImage */
pdfClearDeviceNImage(pdf);