Table 131 – Additional entries specific to a type 6 halftone dictionary

Key

Type

Value

Type

name

(Optional) The type of PDF object that this dictionary describes; if present, shall be Halftone for a halftone dictionary.

HalftoneType

integer

(Required) A code identifying the halftone type that this dictionary describes; shall be 6 for this type of halftone.

HalftoneName

byte string

(Optional) The name of the halftone dictionary.

Width

integer

(Required) The width of the threshold array, in device pixels.

Height

integer

(Required) The height of the threshold array, in device pixels.

TransferFunction

function or name

(Optional) A transfer function, which shall override the current transfer function in the graphics state for the same component. This entry shall be present if the dictionary is a component of a type 5 halftone (see “Type 5 Halftones” in 10.5.5.6 ) and represents either a nonprimary or nonstandard primary colour component (see 10.4, "Transfer Functions" ). The name Identity may be used to specify the identity function.