PassThroughJPEGImages

passThroughJpegImages

Method Name	Argument Name	Argument Type
passThroughJpegImages	status	boolean

If true, JPEG images (images that are already compressed with the DCTEncode filter) are passed through Distiller without re-compressing them. (Distiller does perform a decompression to ensure that images are not corrupt, but then passes the original compressed image to the PDF file.) Images that are not compressed will still be compressed according to the image settings in effect for the type of image (for example, ColorImageFilter , etc.).

If false, all JPEG encoded images are decompressed and recompressed according the compression settings in effect.

However, that JPEG images that meet the following criteria are not passed through even if the value of PassThroughJPEGImages is true:

• The image will be downsampled.

• ColorConversionStrategy is sRGB and the current PostScript color space (for the image) is not DeviceRGB or DeviceGray.

• The image will be cropped—i.e., the clip path is such that more than 10% of the image pixels will be removed.

Creative Suite applications do not use this setting. However, Illustrator and InDesign normally behave as if it were true with regard to placed PDF files containing compressed images. That is, they do not normally uncompress and recompress them, unless color conversion or downsampling takes place.