Bug 232334

Summary: ps2pdf ignores transfer functions in the gradient
Product: Ghostscript Reporter: Alex Cherepanov <alex>
Component: PDF WriterAssignee: Ray Johnston <ray.johnston>
Status: NOTIFIED LATER    
Severity: normal    
Priority: P2    
Version: master   
Hardware: All   
OS: All   
Customer: Word Size: ---

Description Alex Cherepanov 2001-02-14 05:11:18 UTC 
Originally reported by: alexcher@users.sourceforge.net
ps2pdf ignores transfer functions in the shaded fill but
uses them for vector objects. The following sample program
has 2 shaded fills and 2 rectangles that should have the
same color as the left end of the shaded fill.

%!
<</PageSize [612 200] /Policies<</PageSize 1>> >>setpagedevice
612 1 scale
/grad
  { gsave
    0 0 1 100 rectclip
    <</ColorSpace [/DeviceCMYK]
      /Domain [0 1]
      /Coords [0 0 1 0]
      /Extend [false false]
      /Function
        << /FunctionType 3
           /Domain [ 0 1]
           /Functions
             [ << /FunctionType 2
                  /N 1
                  /C0 [ 0 0.5 0 0 ]
                  /Domain [ 0 1]
                  /C1 [0.5 0 0 0]
               >>
             ]
           /Bounds []
           /Encode [0 1]
        >>
      /ShadingType 2
    >> shfill

    0 0.5 0 0 setcmykcolor
    0 0 0.1 50 rectfill
    grestore
  } def

grad
{1 exch 2 div sub} settransfer
0 100 translate
grad
showpage
Comment 1 Ray Johnston 2001-04-05 13:16:06 UTC 
Comment originally by rayjj@users.sourceforge.net
Logged In: YES 
user_id=11206

We acknowledge that this is a valid issue, but we do not have
resources available to address this at this time.

This problem report has been moved to doc/Issues.htm where it
may remain open for some time. Relevant comments are
captured there along with the ID# of this report.

By moving this issue to the widely distributed Ghostscript
documentation, we wish to make this issue well known and
solicit help in improving Ghostscript in this area.

Thanks for your input!