BS ISO 23504-1:2020 pdf free.Document management applications一Raster image transport and storage.
BS ISO 23504-1 Each strip shall be represented by an image X0bject as described in ISO 32000-1:2008, 8.9.5, “Image Dictionaries”. No entries other than Type, Subtype, Length, Filter, DecodeParms, Width, Height,ColorSpace, BitsPerComponent and Intent shall be present.The presence of the entries Subtype, Width, Height, Length is always required. The absence of the
ImageMask key and the absence of the JPXDecode filter (as defined in 6.2.2, “Unencrypted PDF/R files”,and 6.2.3, “Encrypted PDF/R files”) imply that the presence of the ColorSpace entry is also always required.Strips shall be either bitonal, grayscale or RGB images, as defined in 6.6.2, “Bitonal images”, 6.6.3,”Grayscale images’ ‘, and 6.6.4,“RGB images”.All the strips of a page image shall have the same value for the Width entry and shall all contain the same entries for ColorSpace and BitsPerComponent. The effective resolution of the strips of a page
image shall be the same in the Width direction between all strips on the page, and shall be the same in the Height direction between all strips on the page. See Annex A.4, “Reconstructing resolution”, for calculations how to reconstruct the image resolution.RGB images shall be represented by an image X0bject dictionary with ICCBased or CalRGB as the value of its ColorSpace entry, and 8 or 16 as the value for its BitsPerComponent entry.The ICC profile (ISO 15076-1:2010]4] referenced by the ICCBased colour space should represent the
sRGB colour space as defined in IEC 61966-2-1[3], but may represent other colour spaces where deemed necessary. The ICC profile stream dictionary shall contain an Alternate entry which shall have a value of DeviceRGB. See Annex A.8, “Approximate sRBG using CalRGB”, for a simple sRGB approximation example.NOTE 1 As per ISO 32000-1:2008, readers can ignore the ICC profile in an RGB ICCBased colour space.For 8-bit RGB images the Filter entry, if present, shall have a value of DCTDecode or null. For 16-bit RGB images the Filter entry, if present, shall have the value null.NOTE 2This implies that 8-bit images can be JPEG compressed or uncompressed, whereas 16-bit images will always be uncompressed.Annex A.9, “PDF/R example”, presents an example showing the structure of PDF/R files.BS ISO 23504-1 pdf download.