Error using bwareafilt Expected input number 1 to be one of these types:

Greeting I got the above error while using bwareafilt and don`t know what is the wrong

I want to get the biggest region of the grayscale image

so I have uploaded 512*512 size RGB which value is 0 to 255 bmp image and convert it to grayscale image of 512*512 which value is 0 or 1

clear all;
close all;
clc;
img = imread('flower.bmp');
bw=im2bw(img);
bw2=bwareafilt(bw,1,'largest',8);

after I pass my bw image to bwareaflit function it bring outs error

Error using bwareafilt

Expected input number 1 to be one of these types:

logical

Instead its type was double.

I have followed the offical instruction of bwareaflit page but it gives error

I cannot understand what is the wrong

Answer 1

[Pranav Verma]

Hi Mathew,

The bwareafilt function takes a maximum of 3 inputs as parameters, where as you have defined four.

Also instead of using im2bw, you can consider using imbinarize to convert the grayscale image to binary image. To convert the RGB image to grayscale image, you can use rgb2gray function in MATLAB.

Please refer to the documentation on bwarefilt:

https://www.mathworks.com/help/images/ref/bwareafilt.html#buiu1jb-1-keep

Thanks