wat is function of scale and size?

   if size(i,3)>1
    i=rgb2gray(i);

    wat is size(i,3),here i is image and 3 is what

scale=2; if scale>0 here scale gives what

Answer 1

[Pawel Jastrzebski]

size (x,3) calculates the depth of a 3D array.

Function size calculate the dimensions of the array. The additional parameter (1,2,3) tells which size specifically should be calculated.

Consider the examples below and also read on size doc:

% dimensions
x = 5
y = 6
z = 7

% 2D matrix of random values
m2D = rand(x,y)
% 3D matrix of random values
m3D = rand(x,y,z)

% using 'size' on a 2D matrix:
s2D  = size(m2D)    % gives 'x' and 'y' dimensions
s2Dx = size(m2D,1)  % gives 'x' dimension only
s2Dy = size(m2D,2)  % gives 'y' dimension only
s2Dz = size(m2D,3)  % gives 1, as there's no depth

% using 'size' on a 3D matrix:
s3D  = size(m3D)   % gives 'x', 'y' and 'z' dimensions
s3Dx = size(m3D,1) % gives 'x' dimension only
s3Dy = size(m3D,2) % gives 'y' dimension only
s3Dz = size(m3D,3) % gives 'z' dimension only

[Madhava Teja Munagala]

Thank u, wat is the output of these code

[Pawel Jastrzebski]

I don't want to be rude, but can't you run the code yourself to find out the output?

The output is explained in the comments.

>> % dimensions
x = 5
y = 6
z = 7
% 2D matrix of random values
m2D = rand(x,y)
% 3D matrix of random values
m3D = rand(x,y,z)
% using 'size' on a 2D matrix:
s2D  = size(m2D)    % gives 'x' and 'y' dimensions
s2Dx = size(m2D,1)  % gives 'x' dimension only
s2Dy = size(m2D,2)  % gives 'y' dimension only
s2Dz = size(m2D,3)  % gives 1, as there's no depth
% using 'size' on a 3D matrix:
s3D  = size(m3D)   % gives 'x', 'y' and 'z' dimensions
s3Dx = size(m3D,1) % gives 'x' dimension only
s3Dy = size(m3D,2) % gives 'y' dimension only
s3Dz = size(m3D,3) % gives 'z' dimension only

x =

       5

y =

       6

z =

       7

m2D =

      0.1599    0.9759    0.8343    0.9044    0.5714    0.3581
      0.6668    0.0309    0.8136    0.6804    0.9817    0.9869
      0.0179    0.4939    0.6290    0.3788    0.8497    0.0840
      0.1197    0.8627    0.0022    0.6320    0.2834    0.2503
      0.9521    0.2429    0.3797    0.2433    0.6825    0.8113

m3D(:,:,1) =

      0.0844    0.4379    0.9053    0.7831    0.2488    0.9258
      0.5313    0.3504    0.6402    0.6857    0.3193    0.1788
      0.8006    0.4785    0.1629    0.4662    0.9108    0.5175
      0.7388    0.5874    0.5659    0.2603    0.8852    0.6270
      0.1417    0.1458    0.9316    0.5693    0.7946    0.9132

m3D(:,:,2) =

      0.6640    0.0850    0.3801    0.3781    0.6853    0.2602
      0.3892    0.9224    0.8128    0.2489    0.6203    0.8775
      0.7400    0.0536    0.2441    0.2529    0.7467    0.8061
      0.8176    0.5270    0.8844    0.7672    0.9773    0.4611
      0.6003    0.1189    0.7126    0.0499    0.3839    0.0910

m3D(:,:,3) =

      0.5643    0.7267    0.0525    0.9084    0.8506    0.5173
      0.1874    0.5158    0.8012    0.5100    0.1445    0.9905
      0.5317    0.7906    0.6786    0.6149    0.3705    0.2265
      0.3550    0.2045    0.9460    0.3161    0.6224    0.3980
      0.3148    0.6781    0.0916    0.0775    0.9976    0.6966

m3D(:,:,4) =

      0.0646    0.3191    0.7346    0.4968    0.4658    0.2886
      0.7477    0.9861    0.6373    0.0224    0.5609    0.2690
      0.4204    0.7182    0.0738    0.0538    0.4945    0.5942
      0.8113    0.4132    0.1205    0.1409    0.0678    0.4759
      0.3796    0.0986    0.9816    0.8935    0.8976    0.3683

m3D(:,:,5) =

      0.6556    0.4391    0.5199    0.5669    0.0478    0.9374
      0.9382    0.0273    0.0538    0.6804    0.7383    0.5134
      0.6204    0.8762    0.8622    0.3714    0.0380    0.2409
      0.2828    0.6101    0.4429    0.0782    0.9542    0.2600
      0.2052    0.2036    0.5480    0.4564    0.7424    0.7590

m3D(:,:,6) =

      0.9933    0.4306    0.6401    0.3081    0.7598    0.4369
      0.3567    0.7307    0.1320    0.4024    0.2909    0.3043
      0.7529    0.2612    0.4528    0.8842    0.2774    0.2909
      0.1100    0.0948    0.6522    0.7006    0.0061    0.2425
      0.5970    0.4510    0.8270    0.2419    0.3747    0.9367

m3D(:,:,7) =

      0.8602    0.2698    0.3320    0.5433    0.4825    0.1319
      0.3972    0.9897    0.7487    0.2514    0.4427    0.3559
      0.4794    0.1837    0.6444    0.5786    0.3118    0.3959
      0.5650    0.8617    0.1692    0.9155    0.0553    0.8855
      0.4896    0.0326    0.9522    0.8956    0.7538    0.0212

s2D =

       5     6

s2Dx =

       5

s2Dy =

       6

s2Dz =

       1

s3D =

       5     6     7

s3Dx =

       5

s3Dy =

       6

s3Dz =

       7

>>