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In RIP devices, the Halftone screen dot shape code is required, for example: dot code like postscript language - {abs exch abs 2 copy add 1 gt {1 sub dup mul exch add 1 sub dup mul sub} {dup mul exch dup mul add 1 exch sub}, this code should be for hexagonal dot shape, rotogravur will be used in printing. Me hexagonal code required

shumnulu
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This is a highly specialised requirement; if memory serves, gravure halftone spot shapes must never cover 100% of the halftone cell area, because the ink droplet sits in a 'well', which is engraved according to the halftone. If the spot shape ever reaches the edges of the cell then there will be no walls to the well, and the ink will simply flood out.

In addition you want a most unusual dot shape, a hexagon. You haven't given any guidance on how the dot should grow, or what the minimum halftone cell size should be. For example; can the process deal with a single pixel, or is there a minimum size for the spot shape ?

I believe gravure is also normally a very high resolution process and requires highly accurate screens and angles.

In short, I don't think you can generate a satisfactory shape programatically using a spot function, it would certainly be challenging. So I think you would be better advised to look at generating your screen as a threshold array and then using a halftone dictionary with type 3, 4, 6, 10 or 16.

KenS
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  • https://i.hizliresim.com/3660Yr.png. I need the halftone dot shape Postscript code as in the example to me. – shumnulu Feb 19 '19 at 09:52
  • The URL results in an error 403: Forbidden. You also have not addressed any of the points I raised above, nor have you shown any attempt to solve this problem yourself. What code have you come up with so far ? – KenS Feb 19 '19 at 10:25
  • *% Halftone Information =============== *ScreenFreq: "60.0" *ScreenAngle: "45.0" *DefaultScreenProc: Dot *ScreenProc Dot: " {abs exch abs 2 copy add 4 gt {1 sub dup mul exch 1 sub dup mul add 5 sub } {dup mul exch dup mul add 1 exch sub } " *End *ScreenProc Line: "{ pop }" *ScreenProc Ellipse: "{ dup 5 mul 6 div mul exch dup mul exch add 2 exch sub *ScreenProc Hexagonal "{ ????????????}:That's the code in the PPD file. I need the Hexagonal code.????? – shumnulu Feb 19 '19 at 15:07
  • Yeah you still haven't answered any of the questions in my answer, nor have you shown any attempt to build the spot function yourself. This is not a forum for free code. I'm also pretty dubious about using any simple halftone for a gravure process, as I said. What resolution are you going to be rendering at ? – KenS Feb 19 '19 at 16:47