Image Transformation Commands

The following command line arguments to Image to PDF change the contents of an image. These commands can be combined but of course the more image transformation commands that are used the slower the overall conversion will be.

  -Rotate
Parameters: angle - specifies the angle that the image is rotated clockwise by. Must be either 90, 180 or 270 degrees.
Notes:
  • It is not currently possible to rotate the image by any amount - just by the values stated above.
  • This is useful if you have an image acquisition process (eg fax receiving) that produces images that need rotating.
  • If this command is used in conjunction with the -AutoRotate command below, then the rotation specified by this command will only happen if the image has NOT been auto-rotated.
  • This may take some time to complete for larger images.

  •   -AutoRotate
    Parameters: orientation - must be one of the following values:
  • Portrait
  • Landscape

  • angle - specifies the angle that the image is to be rotated clockwise by. Must be either 90 or 270 degrees.
    Notes:
  • Rotates (if required) an image by 90 or 270 degrees so that all images are either in portrait or landscape orientation.
  • This is useful if you have an image acquisition process (eg images received from external sources) that receives images in a variety or orientations when they should all be either portrait or landscape.
  • This may take some time to complete for larger images.

  •   -Flip
    Parameters: orientation - must be one of the following:
  • Vertical
  • Horizontal
  • Both
  • Notes:
  • Horizontal flipping is also known as mirroring.
  • This is useful if you have an image acquisition process (eg web cam) that produces images that may require mirroring.
  • This may take some time to complete for larger images.

  •   -Grayscale
    Parameters: None
    Notes:
  • Converts the image from color into a grayscale equivalent.
  • This is useful if you have an image acquisition process (eg scanning) that produces images that should be grayscale but have a slight color shift.
  • This may take some time to complete for larger images.

  •   -Negative
    Parameters: None
    Notes:
  • Converts the image by inverting the RGB color of each pixel.
  • This may take some time to complete for larger images.

  •   -JpegCompress
    Parameters: quality - specifies the JPEG compression quality, must be a value between 1 (low) and 35 (high).
    Notes:
  • Forces all JPEG images to be re-compressed at the required quality level.
  • A high quality setting will produce better looking images, but at the cost of file size - ie the output PDF will be larger.
  • A reasonable compromise between quality and file size is normally a quality setting of around 25 - this does of course vary depending on the image.
  • This may take some time to complete for larger images.
  • This is the setting used for meta-based embedded full color images when used with the -MetaToNativePDF command.

  •   -NonIntrinsicImageFormat
    Parameters: image format - must be one of the following values:
  • PNG
  • JPG
  • AUTO

  • jpeg quality - specify if image format is JPG or AUTO and is the JPEG compression quality, must be a value between 1 (low) and 35 (high).
    Notes:
  • Determines how non-intrinisc PDF images (i.e. not PNG or JPG ones) are to be auto-converted either always as PNG, JPG or AUTO to help reduce file size.
  • PNG generally produces the highest quality results but with the highest file size as it is a lossless conversion.
  • JPG generally produces variable quality results (depending on the quality level specified) but with smaller file sizes.
  • AUTO is recommended (and is the default if not specified) as it uses PNG format for images that are generally better compressed using this format (i.e. palette based images) and JPG for images with more color in them.
  • We recommend trying parameters of AUTO and 1 and if the JPG quality images are not as good as required use a higher quality value - but 1 is actually not that bad in general.