Previous Next

                                                   222
        CHAPTER 4                                                                         Graphics



KEY      TYPE                  DESCRIPTION

TR       function, array, or   (Optional) The transfer function, which maps the interval [ 0.0 1.0 ] to the in-
         name                  terval [ 0.0 1.0 ] (see Section 6.3, “Transfer Functions”). The value is either a
                               single function (which applies to all process colorants) or an array of four
                               functions (which apply to the process colorants individually). The name
                               Identity may be used to represent the identity function.

TR2      function, array, or   (Optional; PDF 1.3) Same as TR except that the value may also be the name
         name                  Default, denoting the transfer function that was in effect at the start of the
                               page. If both TR and TR2 are present in the same graphics state parameter dic-
                               tionary, TR2 takes precedence.

HT       dictionary, stream,   (Optional) The halftone dictionary or stream (see Section 6.4, “Halftones”) or
         or name               the name Default, denoting the halftone that was in effect at the start of the
                               page.

FL       number                (Optional; PDF 1.3) The flatness tolerance (see Section 6.5.1, “Flatness Toler-
                               ance”).

SM       number                (Optional; PDF 1.3) The smoothness tolerance (see Section 6.5.2, “Smooth-
                               ness Tolerance”).

SA       boolean               (Optional) A flag specifying whether to apply automatic stroke adjustment
                               (see Section 6.5.4, “Automatic Stroke Adjustment”).

BM       name or array         (Optional; PDF 1.4) The current blend mode to be used in the transparent
                               imaging model (see Sections 7.2.4, “Blend Mode,” and 7.5.2, “Specifying
                               Blending Color Space and Blend Mode”).

SMask    dictionary or name    (Optional; PDF 1.4) The current soft mask, specifying the mask shape or
                               mask opacity values to be used in the transparent imaging model (see
                               “Source Shape and Opacity” on page 526 and “Mask Shape and Opacity” on
                               page 550).
                               Note: Although the current soft mask is sometimes referred to as a “soft clip,”
                               altering it with the gs operator completely replaces the old value with the new
                               one, rather than intersecting the two as is done with the current clipping path
                               parameter (see Section 4.4.3, “Clipping Path Operators”).

CA       number                (Optional; PDF 1.4) The current stroking alpha constant, specifying the con-
                               stant shape or constant opacity value to be used for stroking operations in the
                               transparent imaging model (see “Source Shape and Opacity” on page 526 and
                               “Constant Shape and Opacity” on page 551).

ca       number                (Optional; PDF 1.4) Same as CA, but for nonstroking operations.

Previous Next