% rgb.m: translates a colour from multiple formats into matlab colour format
% type 'rgb demo' to get started
%
% [matlabcolor]=rgb(col)
% matlab colors are in the format [R G B]
%
% if 'col' is a string, it is interpreted as
%
% [[modifier] descriptor] colour_name
%
% where
% modifier is one of (slightly, normal, very, extremely)
% descriptor is one of (light/pale, normal, dark)
% colorname is a name of a colour
% (type 'rgb list' or 'rgb demo' to see them all)
%
% if 'col' is an integer between 0 and &HFFFFFF inclusive,
% it is interpreted as a double word RGB value in the form
% [0][R][G][B]
%
% if 'col' is a negative integer between -1 and -&HFFFFFF
% inclusive, it is interpreted as the complement of a double
% word RGB value in the form [0][B][G][R]
%
% if 'col' is a string of the form 'qbX' or 'qbXX' where X
% is a digit then the number part is interpreted as a qbasic
% color
%
% if 'col' is one of {k,w,r,g,b,y,m,c} a sensible result is
% returned
%
% if 'col' is already in matlab format, it is unchanged
% VERSION: 06/06/2002
% AUTHOR: ben mitch
% CONTACT: footballpitch@hotmail.com
% LOCATION: figures\colors\
function out=rgb(in)
if isa(in,'char') & length(in)>2 & length(in)<5 & strcmpi('qb',in(1:2))
out=qbcolor(sscanf(in(3:end),'%i'));
elseif isa(in,'char') & length(in)==1
out=translatecolorchar(in);
elseif isa(in,'char')
if strcmp(in,'demo') rgb_demo; return; end
if strcmp(in,'list') rgb_list; return; end
out=translatecolorstring(in);
elseif isa(in,'double') & size(in,1)==1 & size(in,2)==1 & abs(in)<16777216
out=translatecolorRGB(in);
elseif isa(in,'double') & size(in,1)==1 & size(in,2)==3
out=in;
else
warning('Unrecognised color format, black assumed');
out=[0 0 0];
end
function out=translatecolorchar(in)
switch(in)
case 'k', out=[0 0 0];
case 'w', out=[1 1 1];
case 'r', out=[1 0 0];
case 'g', out=[0 1 0];
case 'b', out=[0 0 1];
case 'y', out=[1 1 0];
case 'm', out=[1 0 1];
case 'c', out=[0 1 1];
otherwise
warning(['Unrecognised colour "' in '", black assumed'])
out=[0 0 0];
return;
end
function out=translatecolorstring(in)
args.tokens=rgb_parse(in);
args.N=length(args.tokens);
if args.N>3 warning('Too many words in color description, any more than 3 will be ignored'); end
while(args.N<3)
args.tokens=[{'normal'};args.tokens];
args.N=args.N+1;
end
cols=get_cols;
col=[];
for n=1:size(cols,1)
names=cols{n,1};
for m=1:length(names)
if strcmp(args.tokens{3},names{m}) col=cols{n,2}; break; end
end
if ~isempty(col) break; end
end
if isempty(col)
warning(['Unrecognised colour "' args.tokens{3} '", black assumed'])
out=[0 0 0];
return;
end
switch args.tokens{1}
case 'slightly', fac=0.75;
case 'normal', fac=0.5;
case 'very', fac=0.25;
case 'extremely', fac=0.125;
otherwise
warning(['Unrecognised modifier "' args.tokens{1} '", normal assumed'])
fac=0.5;
end
switch args.tokens{2}
case {'light','pale'}, out=1-(1-col)*fac;
case 'normal', out=col;
case 'dark', out=col*fac;
otherwise
warning(['Unrecognised descriptor "' args.tokens{2} '", normal assumed'])
out=col;
end
function out=translatecolorRGB(in)
BGR=0;
if in<0
in=-in;
BGR=1;
end
b=bytes4(in);
if BGR out=b(4:-1:2); else out=b(2:4); end
function out=qbcolor(in)
% rgb value from basic colour code
% 0-7 are normal, 8-15 are bright
% 0 - black
% 1 - red, 2 - green, 3 - blue
% 4 - cyan, 5 - magenta, 6 - yellow
% 7 - white
bright=0.5;
if in>7 in=in-8; bright=1; end
switch in
case 0, rgb=[0 0 0];
case 1, rgb=[1 0 0];
case 2, rgb=[0 1 0];
case 3, rgb=[0 0 1];
case 4, rgb=[0 1 1];
case 5, rgb=[1 0 1];
case 6, rgb=[1 1 0];
case 7, rgb=[1 1 1];
otherwise
warning('Unrecognised QBasic color, black assumed');
out=[0 0 0];
return;
end
out=rgb*bright;
function tokens=rgb_parse(str)
% parse string to obtain all tokens
% quoted strings count as single tokens
inquotes=0;
intoken=0;
pos=1;
l=length(str);
st=0;
ed=0;
token='';
tab=char(9);
tokens=cell(0);
while(pos<=l)
ch=str(pos);
if inquotes
if ch=='"'
inquotes=0;
tokens={tokens{:} token};
else
token=[token ch];
end
elseif intoken
if ch==' ' | ch==tab
intoken=0;
tokens={tokens{:} token};
elseif ch=='"'
error(['Quote misplace in <' str '>']);
else
token=[token ch];
end
else
if ch==' ' | ch==tab
% do nothing
elseif ch=='"'
token='';
inquotes=1;
else
token=ch;
intoken=1;
end
end
pos=pos+1;
end
if intoken tokens={tokens{:} token}; end
if inquotes error(['Unpaired quotes in <' str '>']); end
tokens=tokens';
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% DEMO
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function rgb_demo
figure(1)
clf
cols = get_cols;
cols = {cols{:,1}}';
cols = { cols{:}, ...
'k', ...
'r', ...
'g', ...
'b', ...
'y', ...
'm', ...
'c', ...
'w', ...
'', ...
'extremely dark green', ...
'very dark green', ...
'dark green', ...
'slightly dark green', ...
'green', ...
'slightly pale green', ...
'pale green', ...
'very pale green', ...
'extremely pale green', ...
};
height=9;
x=0;
y=0;
for n=1:length(cols)
rect(x,y,cols{n})
y=y+1;
if y==height
x=x+2;
y=0;
end
end
if y==0 x=x-2; end
axis([0 (x+2) 0 height])
title('names on different rows are alternates')
function rect(x,y,col)
if isempty(col) return; end
r=rectangle('position',[x+0.1 y+0.1 1.8 0.8]);
col_=col;
if iscell(col) col=col{1}; end
colrgb=rgb(col);
if strcmp(col(1),'u') & length(col)==2
t=text(x+1,y+0.5,{'unnamed',['colour (' col(2) ')']});
set(r,'facecolor',colrgb);
else
t=text(x+1,y+0.5,col_);
set(r,'facecolor',colrgb);
if sum(colrgb)<1.5 set(t,'color',[1 1 1]); end
end
set(t,'horizontalalignment','center')
set(t,'fontsize',10)
function rgb_list
cols=get_cols;
disp(' ')
for n=1:size(cols,1)
code=cols{n,2};
str=cols{n,1};
str_=[];
for m=1:length(str)
str_=[str_ str{m} ', '];
end
str_=str_(1:end-2);
if strcmp(str_(1),'u') & length(str_)==2
str_=['* (' str_(2) ')'];
end
disp([' [' sprintf('%.1f %.1f %.1f',code) '] - ' str_])
end
disp([10 '* colours marked thus are not named - if you know their' 10 ' designation, or if you feel sure a colour is mis-named,' 10 ' email me (address via help) or comment at' 10 ' www.mathworks.com/matlabcentral - "rgb demo" to see them' 10])
function cols=get_cols
cols={
'black', [0 0 0]; ...
'navy', [0 0 0.5]; ...
'blue', [0 0 1]; ...
'u1', [0 0.5 0]; ...
{'teal','turquoise'}, [0 0.5 0.5]; ...
'slateblue', [0 0.5 1]; ...
{'green','lime'}, [0 1 0]; ...
'springgreen', [0 1 0.5]; ...
{'cyan','aqua'}, [0 1 1]; ...
'maroon', [0.5 0 0]; ...
'purple', [0.5 0 0.5]; ...
'u2', [0.5 0 1]; ...
'olive', [0.5 0.5 0]; ...
{'gray','grey'}, [0.5 0.5 0.5]; ...
'u3', [0.5 0.5 1]; ...
{'mediumspringgreen','chartreuse'}, [0.5 1 0]; ...
'u4', [0.5 1 0.5]; ...
'sky', [0.5 1 1]; ...
'red', [1 0 0]; ...
'u5', [1 0 0.5]; ...
{'magenta','fuchsia'}, [1 0 1]; ...
'orange', [1 0.5 0]; ...
'u6', [1 0.5 0.5]; ...
'u7', [1 0.5 1]; ...
'yellow', [1 1 0]; ...
'u8', [1 1 0.5]; ...
'white', [1 1 1]; ...
};
for n=1:size(cols,1)
if ~iscell(cols{n,1}) cols{n,1}={cols{n,1}}; end
end
% converts a DWORD into a four byte row vector
function out=bytes4(in)
out=[0 0 0 0];
if in<0 | in>(2^32-1)
warning('DWORD out of range, zero assumed');
return;
end
N=4;
while(in>0)
out(N)=mod(in,256);
in=(in-out(N))/256;
N=N-1;
end
