Mercurial > forge
changeset 11664:dba7f31a2ab3 octave-forge
strel: implement ball and 3dline options. Patch by Roberto Metere <roberto@metere.it>
| author | carandraug |
|---|---|
| date | Sun, 28 Apr 2013 03:32:20 +0000 |
| parents | 3863d5c25ae3 |
| children | 7ffd3162121b |
| files | main/image/inst/@strel/strel.m |
| diffstat | 1 files changed, 121 insertions(+), 5 deletions(-) [+] |
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--- a/main/image/inst/@strel/strel.m Sun Apr 28 02:40:25 2013 +0000 +++ b/main/image/inst/@strel/strel.m Sun Apr 28 03:32:20 2013 +0000 @@ -45,6 +45,11 @@ ## @end group ## @end example ## +## @deftypefnx {Function File} {} strel ("ball", @var{radius}, @var{height}) +## Create ball shaped @var{nonflat} structuring element. @var{radius} must be a +## nonnegative integer that specifies the ray of a circle in X-Y plane. @var{height} +## is a real number that specifies the height of the center of the circle. +## ## @deftypefnx {Function File} {} strel ("cube", @var{edge}) ## Create cube shaped @var{flat} structuring element. @var{edge} must be a ## positive integer that specifies the length of its edges. This shape meant to @@ -63,6 +68,12 @@ ## Create line shaped flat structuring element. @var{len} must be a positive ## real number. @var{deg} must be a real number. ## +## @deftypefnx {Function File} {} strel ("3dline", @var{len}, @var{alpha}, @var{phi}) +## Create line shaped flat structuring element in 3D. @var{len} must be a positive +## real number. @var{alpha} is the angle from X-axis to X-Y projection of the line +## and must be a real number. @var{phi} is the angle from Z-axis to the line and +## must be a real number. +## ## @deftypefnx {Function File} {} strel ("octagon", @var{apothem}) ## Create octagon shaped flat structuring element. @var{apothem} must be a ## positive integer that specifies the distance from the origin to the sides of @@ -157,8 +168,26 @@ error ("strel: HEIGHT must be a finite real matrix of the same size as NHOOD"); endif -# case "ball" - ## TODO implement ball shape + case "ball" + if (numel (varargin) == 2) + radius = varargin{1}; + height = varargin{2}; + else + ## TODO implement third option for number of periodic lines approximation + error ("strel: a ball shape needs 2 arguments"); + endif + if (! is_positive_integer (radius)) + error ("strel: RADIUS must be a positive integer"); + elseif (! (isscalar (height) && isnumeric (height))) + error ("strel: HEIGHT must be a real number"); + endif + + # Ellipsoid: (x/radius)^2 + (y/radius)^2 + (z/height)^2 = 1 + # We need only the 1 cells of SE.nhood + [x, y] = meshgrid (-radius:radius, -radius:radius); + SE.nhood = ((x.^2 + y.^2) <= radius^2); # X-Y circle + SE.height = height / radius * SE.nhood .* sqrt (radius^2 - x .^2 - y.^2); + SE.flat = false; case "cube" if (numel (varargin) == 1) @@ -167,7 +196,7 @@ error ("strel: no EDGE specified for cube shape"); endif if (! is_positive_integer (SE.opt.edge)) - error ("strel: EDGE value must be positive integers"); + error ("strel: EDGE value must be a positive integer"); endif SE.nhood = true (SE.opt.edge, SE.opt.edge, SE.opt.edge); @@ -192,7 +221,7 @@ if (numel (varargin) == 1) radius = varargin{1}; else - ## TODO implement second option for number of periodic lines + ## TODO implement second option for number of periodic lines approximation error ("strel: no RADIUS specified for disk shape"); endif if (! is_positive_integer (radius)) @@ -265,7 +294,69 @@ SE.flat = true; - case "octagon" + case "3dline" + if (numel (varargin) == 3) + linelen = varargin{1}; + alpha = varargin{2}; + phi = varargin{3}; + else + error ("strel: a line shape needs 3 arguments"); + endif + if (! (isscalar (linelen) && isnumeric (linelen) && linelen > 0)) + error ("strel: LEN must be a positive real number"); + elseif (! (isscalar (alpha) && isnumeric (alpha))) + error ("strel: ALPHA must be a real number"); + elseif (! (isscalar (phi) && isnumeric (phi))) + error ("strel: PHI must be a real number"); + endif + + ## This is a first implementation + # Stroke line from cells (x1, y1, z1) to (x2, y2, z2) + alpha *= pi / 180; + phi *= pi / 180; + x1 = y1 = z1 = 0; + x2 = round (linelen * sin (phi) * cos (alpha)); + y2 = round (linelen * sin (phi) * sin (alpha)); + z2 = round (linelen * cos (phi)); + # Adjust x2, y2, z2 to have one central cell + x2 += (! mod (x2, 2)) * sign0positive (x2); + y2 += (! mod (y2, 2)) * sign0positive (y2); + z2 += (! mod (z2, 2)) * sign0positive (z2); + # Invert x + x2 = -x2; + + # Tanslate parallelepiped to be in positive quadrant + if (x2 < 0) + x1 -= x2; + x2 -= x2; + endif + if (y2 < 0) + y1 -= y2; + y2 -= y2; + endif + if (z2 < 0) + z1 -= z2; + z2 -= z2; + endif + + # Compute index2es + dim = abs ([(x2 - x1) (y2 - y1) (z2 - z1)]); + m = max (dim); + base = meshgrid (0:m - 1,1) .+ 0.5; + a = floor ((x2 - x1)/m .* base); + b = floor ((y2 - y1)/m .* base); + c = floor ((z2 - z1)/m .* base); + # Adjust indexes to be valid + a -= min (a) - 1; + b -= min (b) - 1; + c -= min (c) - 1; + indexes = sub2ind (dim, a, b, c); + + SE.nhood = false (dim); + SE.nhood(indexes) = true; + SE.flat = true; + + case "octagon" if (numel (varargin) == 1) apothem = varargin{1}; else @@ -371,6 +462,14 @@ retval = isscalar (val) && isnumeric (val) && val > 0 && fix (val) == val; endfunction +function retval = sign0positive (val) + if (sign (val) == -1) + retval = -1; + else + retval = 1; + endif +endfunction + %!shared shape, height %! shape = [0 0 0 1]; %!assert (getnhood (strel (shape)), logical (shape)); @@ -383,6 +482,22 @@ %!assert (getnhood (strel ("arbitrary", shape, height)), logical (shape)); %!assert (getheight (strel ("arbitrary", shape, height)), height); %! shape = [0 0 0 1 0 0 0 +%! 0 1 1 1 1 1 0 +%! 0 1 1 1 1 1 0 +%! 1 1 1 1 1 1 1 +%! 0 1 1 1 1 1 0 +%! 0 1 1 1 1 1 0 +%! 0 0 0 1 0 0 0]; +%! height = [ 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 +%! 0.00000 0.33333 0.66667 0.74536 0.66667 0.33333 0.00000 +%! 0.00000 0.66667 0.88192 0.94281 0.88192 0.66667 0.00000 +%! 0.00000 0.74536 0.94281 1.00000 0.94281 0.74536 0.00000 +%! 0.00000 0.66667 0.88192 0.94281 0.88192 0.66667 0.00000 +%! 0.00000 0.33333 0.66667 0.74536 0.66667 0.33333 0.00000 +%! 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000] +%!assert (getnhood (strel ("ball", 3, 1)), logical (shape)); +%!assert (getheight (strel ("ball", 3, 1)), height); +%! shape = [0 0 0 1 0 0 0 %! 0 0 1 1 1 0 0 %! 0 1 1 1 1 1 0 %! 1 1 1 1 1 1 1 @@ -466,6 +581,7 @@ %!error strel("arbitrary", "stuff") %!error strel("arbitrary", [0 0 1], [2 0 1; 4 5 1]) %!error strel("arbitrary", [0 0 1], "stuff") +%!error strel("ball", -3, 1) %!error strel("diamond", -3) %!error strel("disk", -3) %!error strel("line", 0, 45)