How to multiply the following?

Considering an image I of any size. A mask of size 1X10. How to multiply those two?

[Sivakumaran Chandrasekaran]

a.*b... Most probably it should work

[Sabarinathan Vadivelu]

I'm getting error

??? Error using ==> times
Integers can only be combined with integers of the same class, or scalar doubles.

[Jan]

You cannot multiply a [MxNx3] array directly by a [1x10] vector. It is not clear what kind of output you expect for such a calculation.

Answer 1

[Titus Edelhofer]

Hi,

the error indicates what's wrong: your image and your mask have different types (probably your image is e.g. uint8 and your mask is double). If you need your mask to have non integer values (e.g. 2.345), convert your image to double:

dblImage = double(yourImage);

Otherwise you might try to convert your mask to the same integer type as your image (by using uint8, ...).

Titus

[Sabarinathan Vadivelu]

After converting to the same datatype, I'm getting this error.

??? Subscripted assignment dimension mismatch.

[Jan]

Please post the relevant part of your code. Without the code and without an exact copy of the error message, we can only guess what's going on.

[Sabarinathan Vadivelu]

This is my code. deg0 is 1X10 mask. threshImage is the input Image.

for i=1:10
      deg0(i) = 0.25;
  end
  deg0=cast(deg0,'uint8');
  [rows columns] = size(threshImage);
  for j = 1 : columns
      for i= 1 : 10 : rows
          filtImage0(i,j) = threshImage(i,j).*deg0;
      end
  end

[Titus Edelhofer]

Hi,

if you do it by loop, you need to index deg0 as well:

filtImage0(i,j) = threshImage(i,j).*deg0(i);

or

filtImage0(i,j) = threshImage(i,j).*deg0(j);

Titus