I want to change the black background of my image into white.

rgbImage=imread('C:\Users\KeerthiDev\Desktop\tomato_dataset\Tomato_late_blight_water_mold\late130.jpg');
%figure,imshow(rgbImage, []);
rgbImage = imadjust(rgbImage,stretchlim(rgbImage),[]);
rgbImage = imreducehaze(rgbImage);
figure,imshow(rgbImage);
grayImage = rgb2gray(rgbImage);
figure,imshow(grayImage, []);
hFH = imfreehand();
binaryImage = hFH.createMask();
xy = hFH.getPosition;
blackMaskedImage = grayImage;
blackMaskedImage(~binaryImage) = 0;
maskedRgbImage = bsxfun(@times,rgbImage,cast(binaryImage, 'like',rgbImage));
figure,imshow(maskedRgbImage);

after runing this code to i got the image as shown below

I want to only change this black background to white color (without any other change.)

Answer 1

[Image Analyst]

Try this:

rgbImage = imread('image.png');
subplot(2, 2, 1);
imshow(rgbImage);

mask = all(rgbImage == 0, 3);
% Take the largest blob
mask = bwareafilt(mask, 1);
subplot(2, 2, 2);
imshow(mask);

maskedRgbImage = rgbImage + uint8(255 * repmat(mask, [1, 1, 3]));
subplot(2, 2, 3);
imshow(maskedRgbImage);

[Keerthi D]

Thank you sir .its worked.

[Keerthi D]

sir in that image, some shadow noise is there.how to remove that shadow noise from image

[Image Analyst]

Look for dark pixels, instead of pure black pixels, something like

threshold = 20; % gray levels or whatever you want.
mask = all(rgbImage <= threshold, 3);

[Keerthi D]

where to give this code.

[Keerthi D]

I wanted to crop the give below image.

[Image Analyst]

Well that code would replace the existing code that creates the mask. So replace this

mask = all(rgbImage == 0, 3);

with this

threshold = 20; % gray levels or whatever you want.
mask = all(rgbImage <= threshold, 3);

To crop an image, you can use imcrop().

[Keerthi D]

I replaced mask = all(rgbImage ==0,3); with

threshold = 20; % gray levels or whatever you want.

mask = all(rgbImage <= threshold, 3);

but it not work.it show like this.

[Image Analyst]

I'm not sure what you're wanting. Do you want the surround to be white or black? Do you want the image cropped smaller or not? If so, where would you want the cropping rows and columns to be?

[Keerthi D]

surround should be white.my problem is,some shadows are presented inside and outside of the leaf.how to remove both are.

[Image Analyst]

Try the attached article.

[Keerthi D]

I didn't get

[Image Analyst]

Well, keep trying. I don't have that paper coded up myself, so you'll have to do it. But it looks like it should remove your shadows.