why cant i run this simple function?

hello people, i have to create a simple function but it doesnt work

function [blackLevel, asShotNeutral] = evc_read_file_info(filename)
     img = imfinfo(filename); %reads infos in the filename
     blackLevel =img.BlackLevel; % gives back BlackLevel from the file
     asShotNeutral = img.AsShotNeutral; %gives back AsShotNeutral from the file
end

function [result] = evc_transform_colors(input, blackLevel)
  maxSampleValue = img.MaxSampleValue; % gives maxSampleValue from the file which is up
  result = (double(input)-blackLevel)/ (maxSampleValue - blackLevel); %makes 'input' double , moves and scales the contrast in intervall [0,1] instead of [BlackLevel,65535]
end

can anyone tell me whats wrong with it? what am i doing wrong???

[Ced]

What is the problem with it? Are you aware that you won't be able to call evc_transform_colors from outside this m-file? You need to place it into a separate file.

img is not defined in the second function.

PS: You also have a & instead of a % in your second function.

[Alprcnkt]

these are part of the main funtion , i dont need to call this two functions it gives an error if i call the main funtion on line "img = imfinfo(filename);" i dont know about rest tell me if you know whats wrong

[Ced]

What is the error message? There is nothing wrong with that line as such.

[John BG]

making the image available would also help

[Alprcnkt]

guys i m really out of everything pls help me the whole is in the first message already but why cant i call and use this?

 function [result, asShotNeutral, fnc_read_file_info,fnc_tranform_colors] = evc_black_level(input, filename) %main Function
       fnc_read_file_info  = @(filename)   evc_read_file_info (filename);
   fnc_tranform_colors = @(input, blackLevel)   evc_transform_colors(input, blackLevel);
          
        [blackLevel, asShotNeutral] = evc_read_file_info(filename);  
        result = evc_transform_colors(input, blackLevel);
 end

function [blackLevel, asShotNeutral] = evc_read_file_info(filename)
    info = imfinfo(filename); % gives error (not enough input arguments)
    blackLevel =info.BlackLevel;
    asShotNeutral = info.AsShotNeutral;
end

function [result] = evc_transform_colors(input, blackLevel)
     input = 'IMG_5.tiff';
     blacklevel = input.BlackLevel;
     maxSampleValue = input.MaxSampleValue;
     result = (double(input)-blackLevel)/ (maxSampleValue - blackLevel); 
end

[Ced]

How are you calling your function?

Answer 1

[Walter Roberson]

Either you are not passing a string to evc_read_file_info, or else the string does not refer to an image file. One way it can go wrong is if you pass only the name and extension of a file that is not in the current directory, having forgotten to add the directory information to it.