pdfWritePageBitmap

This function converts a PDF page to an image file on disk.

The arguments are:

• page = page number
• dpi = resolution (dots per inch)
• color = color setting - one of:
  • pdfImageMono: 1-bit monochrome
  • pdfImageGray: 8-bit grayscale
  • pdfImageRGB: 8-bit RGB
  • pdfImageCMYK: 8-bit CMYK
  • pdfImageDevNToCMYK: 8-bit CMYK, rasterized in DeviceN and then converted to CMYK
  • pdfImageDevNToRGB: 8-bit RGB, rasterized in DeviceN and then converted to RGB
  • pdfImageGrayToMono: 1-bit monochrome, rasterized in 8-bit grayscale and then converted to 1-bit
• format = image file format - one of:
  • pdfImageFileBMP: Windows BMP format
    (available for mono, gray, RGB, DevNToRGB, GrayToMono)
  • pdfImageFileTIFF: uncompressed TIFF format
    (available for mono, gray, RGB, CMYK, DevNToCMYK, DevNToRGB, GrayToMono)
  • pdfImageFileJPEG: JPEG format
    (available for gray, RGB, CMYK, DevNToCMYK, DevNToRGB)
  • pdfImageFilePNG: PNG format
    (available for mono, gray, RGB, DevNToRGB, GrayToMono)
  • pdfImageFilePNM: PBM (monochrome), PGM (grayscale), or PPM (RGB) file - these formats are more commonly used on Unix (but are available in all versions of XpdfRasterizer)
    (available for mono, gray, RGB, DevNToRGB, GrayToMono)
• fileName = image file name

The pdfImageDevNToCMYK mode produces CMYK output like pdfImageCMYK, but does the rasterization in DeviceN (CMYK + spot colors) so overprint previews will be more accurate.

The pdfImageDevNToRGB mode is similar to pdfImageDevNToCMYK, but converts to RGB output.

The pdfImageGrayToMono mode does the rasterization in 8-bit grayscale and converts to 1-bit monochrome at the end. This is useful for files that use transparency – because 1-bit monochrome mode doesn't support transparency.

CMYK output is only available in TIFF format.