On 2014-06-18 19:13, Pascal Obry wrote: > Another iteration. I've added a version number to avoid confusion. Also > a nice :) ASCII art! > > >> Design Notes for the Print Module >> ================================= >> >> Version: 3 >> >> This is the initial goal for the print module. It supports a single print, >> one image per page. Adding templates, multi-images per page, rotation... will >> be discussed later if there is needs for it. But as dt is a professional >> photo >> application I'm not sure this is a goal for dt. At least some other software >> around are dedicated to "fun" printing. >> >> On important goal after the first iteration is that dt should not add >> dependencies if possible. This second design notes are using plain >> Gtk+ services. No CUPS API, not Gutenprint or whatever. We realy on >> what/how printers are configured on the systems. Be it on CUPS or >> whatever and using whatever backend (hplip, gutenprint...). >> >>
For *the future*: Support for printing ONE image larger than one sheet of paper, in the meaning that 1) DT picks out crops of a single image (preferably resided by user) 2) Adds inter-sheet overlap-borders (for glue or tape; either top/bottom and either side) 3) Prints each crop on one sheet (as supported by the printer). NOTE: The choice of which side to have the inter-sheet overlap has to be decided with the display position in mind. The overlapping parts of paper will show a shadow unless facing the light. ASCII "Sketch" (let's hope it comes through without distortion): "i" and "=" inter-sheet overlap, selectable top/bottom and left/right side of sheet. "x" -- some sort of rod (wood/steel) to keep the mounted sheets in place when hung on wall. Edges of outermost sheets with similar border as for normal prints. All borders adjustable, paper type and size determines how much one needs for glue/tape. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx +--------+--------+--------+ | i i | | i i | | i i | | i i | | i i | | i i | +========+========+========+ | i i | | i i | | i i | | i i | | i i | | i i | +========+========+========+ | i i | | i i | | i i | | i i | | i i | | i i | +--------+--------+--------+ Regrading mounting the sheets together: 3x3 sheets is quite doable *by* *hand* in my opinion, using more sheets is harder - might require help/tools for straightening for good results. Single row of sheets may be easier in this regard. A dedicated paper cutter is a great help https://www.google.se/?gfe_rd=cr&safe=off#q=+paper+cutter&safe=off Three small pieces of tape per side on the backside - good for holding A4-sheets, dedicated paper glue is perfect. Glue might be the better choice on larger prints. Mobile phone photo of mock-up: https://www.dropbox.com/s/f48l3cuqo2w2rp1/2014-06-19%2017.42.39.png How large can one print then? Limit of largest practical print is determined by "Circle of Confusion"; with the smallest details in an image covering an angle of 1/30 degree of view is VISIBLE for a person with normal eyes will notice it. Which means that VIEWING DISTANCE matters when you print very large from a "low resolution" image. So, help to determine the shortest viewing distance from image data is just a calculation away. i.e. how large will a single pixel print -> the measure should not be as large as 1/30 degree, or the print will appear slightly blurred - assuming the image itself is immensely sharp. -- /Hannu ------------------------------------------------------------------------------ HPCC Systems Open Source Big Data Platform from LexisNexis Risk Solutions Find What Matters Most in Your Big Data with HPCC Systems Open Source. Fast. Scalable. Simple. Ideal for Dirty Data. Leverages Graph Analysis for Fast Processing & Easy Data Exploration http://p.sf.net/sfu/hpccsystems _______________________________________________ darktable-devel mailing list darktable-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/darktable-devel
