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From: Mojca M. <moj...@gm...> - 2011-12-13 22:20:04
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Hello,
I just remembered that implementation of monochrome option in context
terminal is slightly suboptimal (in standalone mode it lets TeX do
color conversion into gray scale as "rgb2gray").
I should probably fix that, but I'm not sure what exactly to do:
should I simply make all the colors black or should I use different
shades of gray, and in the second case - which colors exactly?
Thank you,
Mojca
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From: Ethan A M. <sf...@us...> - 2011-12-13 22:33:09
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On Tuesday, December 13, 2011 02:19:58 pm Mojca Miklavec wrote: > Hello, > > I just remembered that implementation of monochrome option in context > terminal is slightly suboptimal (in standalone mode it lets TeX do > color conversion into gray scale as "rgb2gray"). > > I should probably fix that, but I'm not sure what exactly to do: > should I simply make all the colors black or should I use different > shades of gray, and in the second case - which colors exactly? In my opinion, which may not be universally shared, 'set term foo monochrome' should cause it to choose a default palette in shades of grey, and a default set of lines that are not colored. But it should not prevent the user from drawing explicitly in whatever color they like, and it should not prevent the user from selecting a color palette later. I see it as exactly analagous to "set term foo dashed", which defaults to dashed lines but does not stop you from explictly drawing with solid lines instead, or "set term foo font 'blah'", which doesn't stop you from changing the font later. Ethan > Thank you, > Mojca > > ------------------------------------------------------------------------------ > Systems Optimization Self Assessment > Improve efficiency and utilization of IT resources. Drive out cost and > improve service delivery. Take 5 minutes to use this Systems Optimization > Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/ > _______________________________________________ > gnuplot-beta mailing list > gnu...@li... > https://lists.sourceforge.net/lists/listinfo/gnuplot-beta > |
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From: Mojca M. <moj...@gm...> - 2011-12-14 00:37:39
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On Tue, Dec 13, 2011 at 23:32, Ethan A Merritt wrote: > On Tuesday, December 13, 2011 02:19:58 pm Mojca Miklavec wrote: >> Hello, >> >> I just remembered that implementation of monochrome option in context >> terminal is slightly suboptimal (in standalone mode it lets TeX do >> color conversion into gray scale as "rgb2gray"). >> >> I should probably fix that, but I'm not sure what exactly to do: >> should I simply make all the colors black or should I use different >> shades of gray, and in the second case - which colors exactly? > > In my opinion, which may not be universally shared, > 'set term foo monochrome' should cause it to choose a default palette > in shades of grey, and a default set of lines that are not colored. On the other hand, mochrome means "mono" (= single color). I understand the second. The colors lc 1, lc 2, ... should be gray, except that I would be grateful for some proposal of which shades of gray exactly. But what exactly is meant with default palette? PM3D? But how can a terminal influence the choice of palette formulas? > But it should not prevent the user from drawing explicitly in whatever > color they like, and it should not prevent the user from selecting a > color palette later. What exactly do you mean with selecting a color palette? (Probably the same question as earlier.) > I see it as exactly analagous to "set term foo dashed", which > defaults to dashed lines but does not stop you from explictly > drawing with solid lines instead Yes, but solid line is one particular type of dashed line (one can always draw with "lt 0 lc 3"), while the opposite is not true. If one selects "solid", it is impossible to draw dashed lines later. In the same way, if one chooses "color", one can always plot with "lc 0" (black) or with proper black since black is just one type of color. (If analogy with dashes was true, one would not be able to draw in color once monochrome is selected. On the other hand there exists a mechanism to set colors explicitly as rgb values, but no mechanism to set an explicit dash type [unless I'm mistaken].) Mojca |
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From: sfeam (E. Merritt) <eam...@gm...> - 2011-12-14 02:37:46
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On Tuesday, 13 December 2011, Mojca Miklavec wrote: > On Tue, Dec 13, 2011 at 23:32, Ethan A Merritt wrote: > > On Tuesday, December 13, 2011 02:19:58 pm Mojca Miklavec wrote: > >> Hello, > >> > >> I just remembered that implementation of monochrome option in context > >> terminal is slightly suboptimal (in standalone mode it lets TeX do > >> color conversion into gray scale as "rgb2gray"). > >> > >> I should probably fix that, but I'm not sure what exactly to do: > >> should I simply make all the colors black or should I use different > >> shades of gray, and in the second case - which colors exactly? > > > > In my opinion, which may not be universally shared, > > 'set term foo monochrome' should cause it to choose a default palette > > in shades of grey, and a default set of lines that are not colored. > > On the other hand, mochrome means "mono" (= single color). Like black and white photography? Black and white movies? > I understand the second. The colors lc 1, lc 2, ... should be gray, > except that I would be grateful for some proposal of which shades of > gray exactly. Do you really mean "lc"? Why would you use that if not to set colors? The default sequence of line _types_ should IMHO all be black, for better reproduction in print. Use "set term post mono dashed" as a model. Something like solid / dot / thick / dash / dot-dot-dash But really in version 4.5 you don't need a special terminal option for this. You would just need to load a "mono" set of linetypes. > But what exactly is meant with default palette? PM3D? But how can a > terminal influence the choice of palette formulas? Again look at the postscript terminal. A greyscale palette is really easy. It doesn't need any formulae unless you want to get fancy and handle gamma correction. Ethan > > But it should not prevent the user from drawing explicitly in whatever > > color they like, and it should not prevent the user from selecting a > > color palette later. > > What exactly do you mean with selecting a color palette? (Probably the > same question as earlier.) > > > I see it as exactly analagous to "set term foo dashed", which > > defaults to dashed lines but does not stop you from explictly > > drawing with solid lines instead > > Yes, but solid line is one particular type of dashed line (one can > always draw with "lt 0 lc 3"), while the opposite is not true. If one > selects "solid", it is impossible to draw dashed lines later. > > In the same way, if one chooses "color", one can always plot with "lc > 0" (black) or with proper black since black is just one type of color. > (If analogy with dashes was true, one would not be able to draw in > color once monochrome is selected. On the other hand there exists a > mechanism to set colors explicitly as rgb values, but no mechanism to > set an explicit dash type [unless I'm mistaken].) > > Mojca > |
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From: Daniel J S. <dan...@ie...> - 2011-12-14 03:18:44
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On 12/13/2011 06:37 PM, Mojca Miklavec wrote: > On Tue, Dec 13, 2011 at 23:32, Ethan A Merritt wrote: >> On Tuesday, December 13, 2011 02:19:58 pm Mojca Miklavec wrote: >>> Hello, >>> >>> I just remembered that implementation of monochrome option in context >>> terminal is slightly suboptimal (in standalone mode it lets TeX do >>> color conversion into gray scale as "rgb2gray"). >>> >>> I should probably fix that, but I'm not sure what exactly to do: >>> should I simply make all the colors black or should I use different >>> shades of gray, and in the second case - which colors exactly? >> >> In my opinion, which may not be universally shared, >> 'set term foo monochrome' should cause it to choose a default palette >> in shades of grey, and a default set of lines that are not colored. > > On the other hand, mochrome means "mono" (= single color). > I understand the second. The colors lc 1, lc 2, ... should be gray, > except that I would be grateful for some proposal of which shades of > gray exactly. What object is it exactly that the monochrome qualifier refers to? Lines, images, symbols? All of the above? Monochrome means as you say, a single color or point on the chromatic scale. However, I'd say that greyscale is a special type of monochrome. The thing that varies in monochrome is the intensity of the light source (i.e., pixel) while the color components remain fixed, relatively speaking. Greyscale is a monochrome in which all primary components are weighted equally. However, one could create a monochrome image where the color components (RGB) are not weighted equally. Examples of this would be well known historic photographic prints that, for example, have a sepia tone. So with the "monochrome" option, I'd suggest a second qualifier option which is the RGB components. (We must have a standard way of expressing RGB by now. Names might work too.) For example, set term foo monochrome (1,0.8,0.5) set term foo monochrome red [above is equivalent to "set term foo monochrome (1,0,0)"] set term foo monochrome sepia Thoughts? > But what exactly is meant with default palette? PM3D? But how can a > terminal influence the choice of palette formulas? > >> But it should not prevent the user from drawing explicitly in whatever >> color they like, and it should not prevent the user from selecting a >> color palette later. > > What exactly do you mean with selecting a color palette? (Probably the > same question as earlier.) Color palette is different from monochrome and different from RGB. Palette is a series of colors acting as a look-up-table for various values. Give the LUT a value of 3 and it returns a triple representing the RGB values. The palette can be asigned vary strange color combinations to create various effects, e.g., weather map, cartography, so on. Dan |
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From: Tait <gnu...@t4...> - 2011-12-14 21:45:59
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> set term foo monochrome (1,0.8,0.5) > set term foo monochrome red > [above is equivalent to "set term foo monochrome (1,0,0)"] > set term foo monochrome sepia > > Thoughts? My first thoughts are, "is that useful?" "is it necessary?" But if we do go that route, I see no reason to limit the possibilities to a linear arithmetic weighted average. If one wants a nonlinear dependence on one or more of the color channels, the more general solution would be something like "set term foo monochrom using ((2.0*$1**2+$2+$3)/(2*255**2+2*255))" or replace 255 with 1.0 if we're using a 0-1.0 scale instead of 0-255. I am assuming $1, $2, $3 are red, green, blue respectively. |
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From: Daniel J S. <dan...@ie...> - 2011-12-14 22:27:36
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On 12/14/2011 03:45 PM, Tait wrote: >> set term foo monochrome (1,0.8,0.5) >> set term foo monochrome red >> [above is equivalent to "set term foo monochrome (1,0,0)"] >> set term foo monochrome sepia >> >> Thoughts? > > My first thoughts are, "is that useful?" "is it necessary?" Don't know. Could be to a small percentage of people, but if it is an easily implemented thing then perhaps it is worth making the feature available. I searched for some examples of sepia tone. Here are a few: http://akvis.com/en/coloriage-tutorial/examples/sepia-photo.php http://www.pxleyes.com/photography-picture/4bb664349c057/Civita.html http://www.eltonography.com/albums/STANDARD/TCONN.html My point is that I would call the above monochrome, but not greyscale. > But if we do go that route, I see no reason to limit the possibilities > to a linear arithmetic weighted average. If one wants a nonlinear > dependence on one or more of the color channels, the more general > solution would be something like "set term foo monochrom using > ((2.0*$1**2+$2+$3)/(2*255**2+2*255))" or replace 255 with 1.0 if we're > using a 0-1.0 scale instead of 0-255. I am assuming $1, $2, $3 are red, > green, blue respectively. Actually, what you are describing is something different. I was describing the monochrome scale; you are describing the input mapping. Let's see if I can draw a little I/O diagram: ------------ ---------- RGB values | I(R,G,B) | |a_r*mono|--> R or -->| or |--> mono values -->|a_g*mono|--> G Mono values |no mapping| |a_b*mono|--> B ------------ ---------- The formula you have given would be I(R,G,B) in the above diagram. (a_r,a_g,a_b) are the weighting parameters that I was describing. And for greyscale, a_r=1, a_g=1, a_b=1. I think, and I may be wrong, that currently one could apply the formula you are describing at the point of reading data from an image file. Manipulating a_r, a_g, a_b would be possible as well, but with slightly more complex manipulations of input data. Dan |
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From: Daniel J S. <dan...@ie...> - 2011-12-14 22:50:01
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On 12/14/2011 04:27 PM, Daniel J Sebald wrote: > http://akvis.com/en/coloriage-tutorial/examples/sepia-photo.php Actually, reading this whole tutorial is useful as J.C.G. addresses all the things we've discussed, e.g., first creating a b&w image from a color image (otherwise skip those steps) and messing around with hue/saturation to adjust the sepia appearance. Dan |
