[Gzz-commits] gzz/Documentation/Manuscripts/Paper paper.tex

[Janne V. Kujala]

CVSROOT:        /cvsroot/gzz
Module name:    gzz
Changes by:     Janne V. Kujala <address@hidden>        02/11/22 05:18:08

Modified files:
        Documentation/Manuscripts/Paper: paper.tex 

Log message:
        colors

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/Documentation/Manuscripts/Paper/paper.tex.diff?tr1=1.53&tr2=1.54&r1=text&r2=text

Patches:
Index: gzz/Documentation/Manuscripts/Paper/paper.tex
diff -u gzz/Documentation/Manuscripts/Paper/paper.tex:1.53 
gzz/Documentation/Manuscripts/Paper/paper.tex:1.54
--- gzz/Documentation/Manuscripts/Paper/paper.tex:1.53  Fri Nov 22 04:31:27 2002
+++ gzz/Documentation/Manuscripts/Paper/paper.tex       Fri Nov 22 05:18:08 2002
@@ -324,24 +324,25 @@
 
 \subsection{Colors}
 
-Color is the most dominant visual attribute of a paper. 
+Color is the most dominant visual attribute of a background. 
 Therefore, it is essential that the perception of the coloring 
-of the textures is as uniform as possible. % XXX ***WHAT*** does this mean?
+of the backgrounds is as uniform as possible. % XXX ***WHAT*** does this mean?
 
-Using multiple different colors in a texture allows 
+Using multiple different colors in a background allows 
 a multitude of different combinations 
-but too many different colors in one texture are perceived just 
-as a mix of many colors, making all such textures look the same.
-% XXX Connect with "random pixels" example
+but too many different colors in one background are perceived just 
+as a mix of many colors, making all such backgrounds look the same.
+%XXX: 
+Connect with "random pixels" example
 
-Therefore, we use a small palette of carefully chosen colors for each texture,
-independent of the basis textures producing the shape of the final texture. 
+Therefore, we use a small palette of carefully chosen colors for each 
background,
+independent of the basis textures producing the shapes of the background. 
 Register combiners are used to combine the shape with the colors 
 as explained in the following sections.
 
-The most important constraint for the colors is readability:
-black text must have good contrast with the texture.
-% XXX This is our CHOICE for a goal, not an absolute one.
+Black text should have good contrast with the background.
+%The most important constraint for the colors is readability:
+%% XXX This is our CHOICE for a goal, not an absolute one.
 Additionally, the colors should be perceptually uniformly distributed
 and ``balanced'' to avoid overloading of color perception.
 % "Overloading"? 
@@ -349,10 +350,12 @@
 Usually color perception is divided to lightness, hue, 
 and saturation (the chromatic purity), which are nonlinearly
 related to the usual RGB values.
-The are many nonlinear color spaces, such as CIE $L^*a^*b^*$ 
-\cite{cie86colorimetry}, 
-designed to represent the perceived components of color 
-on a uniform scale.
+A color space is called perceptually uniform, if the Euclidian
+distance of coordinates approximately corresponds to the
+perceived difference of color.
+For example, the CIE $L^*a^*b^*$ \cite{cie86colorimetry}
+color space is reasonably perceptually uniform.
+
 % Uniform? 
 %  1) define term
 %  2) not really uniform; it's MORE uniform than RGB but not
@@ -361,30 +364,30 @@
 To address readability, we only use colors with the CIE $L^*$
 lightness value over 80 (percent of maximum).
 % Mention screen gamma earlier, maybe here.
-However, because the texture shapes should also be visible, 
-we use one half dark colors and one half light colors in the 
-range to have some contrast for the shapes.
-% Mention unpleasant visual effect from textures with only 
-% chroma changes. Having contrast makes shapes distinguishable
-Even though the register combiners interpolate linearly between 
-the colors in the palette, the lightness of an intermediate
-color is still between the two colors, because perceived
-lightness is a monotonous function of luminance.
-% Doesn't really need to be said here; it's what people
-% will naturally assume.
 For correct computation of the color lightness, 
-it is essential that the display gamma is adjusted properly
+it is essential that the display gamma is properly adjusted
 for linear RGB reproduction.
 % Onko lineaarinen *varmasti* oikea LAB-muunnokselle?
+Because the shapes should also be distinguishable, 
+we use one half dark colors and one half light colors in the 
+range to have some contrast for the shapes.
+This avoids the unpleasant, blurry appearance of backgrounds with only 
+chroma changes in colors. 
+%Having contrast makes shapes distinguishable
+
+%Even though the register combiners interpolate linearly between 
+%the colors in the palette, the lightness of an intermediate
+%color is still between the two colors, because perceived
+%lightness is a monotonous function of luminance.
+%% Doesn't really need to be said here; it's what people
+%% will naturally assume.
 
 To have balanced colors, we choose the hues from a distribution
 % To have: huonoa englantia
 concentrated on one random hue with a random variance and
 saturations chosen from an ad hoc distribution.
 This produces related colors with high probability, but still
-allows flashy palettes to occur occasionally.
-% flashy? flashy = hienosteleva...
-% motley parempi?
+allows motley palettes to occur occasionally.
 
 Because the $a^*b^*$ plane of the CIE $L^*a^*b^*$ color space seems to 
 have too large angle of blue for light colors,