How to make gif images from a set of images in matlab? - image

How to make '.gif' image from a set of '.jpg' images (say: I1.jpg, I2.jpg,..., I10.jpg) in matlab?

Ok here is a simple example. I got an image with a unicorn on it and remove 2 part to create 3 different images, just for the sake of creating an animated gif. Here is what it looks like:
clear
clc
%// Image source: http:\\giantbomb.com
A = rgb2gray(imread('Unicorn1.jpg'));
B = rgb2gray(imread('Unicorn2.jpg'));
C = rgb2gray(imread('Unicorn3.jpg'));
ImageCell = {A;B;C};
figure;
subplot(131)
imshow(A)
subplot(132)
imshow(B)
subplot(133)
imshow(C)
%// Just to show what the images look like (I removed spots to make sure there was an animation created):
%// Create file name.
FileName = 'UnicornAnimation.gif';
for k = 1:numel(ImageCell)
if k ==1
%// For 1st image, start the 'LoopCount'.
imwrite(ImageCell{k},FileName,'gif','LoopCount',Inf,'DelayTime',1);
else
imwrite(ImageCell{k},FileName,'gif','WriteMode','append','DelayTime',1);
end
end
As you see, its not that different from the example on the Mathworks website. Here my images are in a cell array but yours might be in a regular array or something else.That should work fine; when I open 'UnicornAnimation.gif' it is indeed a nice animation!
Hope that helps!

Related

Rice grain Segmentation in Matlab

I have an image of multiple rice grains in jpg format. I need to separate the individual rice grains into a separate images.
The input image is as below:
The resultant images should contain individual rice as below:
Currently I am using the following code:
close all;
BW = imread('img11_Inp','jpg');
L = bwlabel(BW)
figure
imshow(BW);
CC = bwconncomp(L);
stats = regionprops(L,'Image');
stats
%Display the first component as an image
Image1 = stats(2).Image
figure
imshow(Image1);
There are two problems with this code. Firstly, it is showing only two images rice grains in the "stats" structure and secondly it is also showing some noise. Please let me know what is the problem with this code
Look at this code with the comments
close all;
clear
I = imread('rice.jpg'); % jpg add noise. TODO: use png format
level = graythresh(I); % Global image threshold using Otsu's method
BW1 = imbinarize(I,level); % need to threshold, jpg add low level noise.
BW2 = imfill(BW1,'holes'); %fill holes inside grains
[L,n] = bwlabel(BW2); % label connected components
B = labeloverlay(I,L);
figure('Name',sprintf('NLables=%d',n)); imshow(B);
stats = regionprops(L,{'Centroid','Area'});
for i=1:length(stats)
x=stats.Centroid(i,1);
y=stats.Centroid(i,2);
area=stats.Area(i);
text(x,y,sprintf('Area=%d',area),'FontSize',8);
end

for loop causing bad text segmentation in matlab

the input images are a.jpg and b.jpg
these two image stored in for example comp folder.and want to write the segmented image in segment folder.but I think for looping problem segmentation repeated for so many times for each image.And I could't solve the problem.
here is my code
Resultado='C:\Users\Nurul\Desktop\picsegment';
srcFiles = dir('C:\Users\Nurul\Desktop\comp\*.jpg');
for i = 1 : length(srcFiles)
filename = strcat('C:\Users\Nurul\Desktop\comp\',srcFiles(i).name);
a = imread(filename);
LLL=a;
s=regionprops(LLL);
figure,imshow(LLL); title('segmented Image');
hold on
for J=1:numel(s)
rectangle('Position',s(J).BoundingBox,'edgecolor','g')
end
im1=LLL;
baseFileName = sprintf('%d.jpg', i); % e.g. "1.png"
fullFileName = fullfile(Resultado, baseFileName);
imwrite(im1, fullFileName);
end
plz help
thanks
You are saving your data as jpg, big mistake!
Still, if you want to keep the data saved as jpg, remember that it will not be saved as a binary image, and that means you need to binarize it again! Otherwise, every little pixel noise will be detected as data by regionprops, thats why you get so many squares.
Just add
a = imread(filename);
a=im2bw(a,0.5); % Add this line. The fancy way would be im2bw(a,graythresh(a)), but 0.5 will do in your case
LLL=a;

Image blending with mask

I'm trying to combine the two images based on the information from the mask. I'm using the color information from the background image if the mask is 0 and color information from foreground image if the mask is 1. Because the mask and both
Images are of the same size, I would like to use logical indexing of matrices to achieve this.
My attempt:
mask = imread('mask.png');
foreground = imread('fg.jpg');
background = imread('bg.jpg');
[r,c,~]=size(mask);
A = zeros(size(mask));
for i=1:r
for j=1:c
if mask(i,j) == 0
A(i,j,:) = background(i,j,:);
end
if mask(i,j) > 0
A(i,j,:) = foreground(i,j,:);
end
end
end
imshow(A);
The result looks like a flickering blue image, but I don't want that. Please help.
You can do this a bit more concisely:
f = double(foreground).*double(mask);
b = double(background).*double(~mask);
blend = f+b;
imshow(blend, []);
Using logical indexing you could also do
foreground(logical(mask)) = 0;
background(logical(~mask)) = 0;
blend = foreground+background;
The ISNOT operator '~' inverts your matrix in the second line, so you cut out the area you would like for background.
NOTE: This works for black and white (one channel). For coloured images see rayryeng's solution.
There are two problems with your code. The first problem is that you are trying to assign colour pixels to the output image A, yet this image is only two-dimensional. You want an image with three channels, not two. In addition, the output image type you are specifying is wrong. By default, the output image A is of type double, yet you are copying values into it that aren't double... most likely unsigned 8-bit integer.
As such, cast the image to the same type as the input images. Assuming both input images are the same type, initialize your A so that:
A = zeros(size(foreground), class(foreground));
This correctly makes a colour image with the same type as any of the inputs, assuming that they're both the same type.
Now, your for loop is fine, but it's better if you do this in one shot with logical indexing. If you want to use logical indexing, create a new image that's initially blank like what you've done, but then make sure your mask has three channels to match the number of channels the other images have. After, you simply need to index into each image and set the right locations accordingly:
mask = imread('mask.png');
foreground = imread('fg.jpg');
background = imread('bg.jpg');
[r,c,d]=size(mask); %// Change
%// If your mask isn't three channels, make it so
%// Change
if d ~= 3
mask = cat(3, mask, mask, mask);
end
A = zeros(size(foreground), class(foreground)); %// Change
A(mask) = foreground(mask); %// Assign pixels to foreground
A(~mask) = background(~mask); %// Assign pixels to background
imshow(A);

How do I save an image generated by imshow(image) into a variable?

This is my code. I want to save the image displayed on imshow(img) into a variable to use it later. Thanks!
img=imread('image1.bmp');
figure(1), imshow(img);
[r c]=ginput(4);
Bw=roipoly(img,r,c);
% figure,imshow(Bw)
[R C]=size(Bw);
for i=1:R
for j=1:C
if Bw(i,j)==1
img(i,j)=img(i,j);
else
img(i,j)=0;
end
end
end
figure,
imshow(img); title ('Output Image');
You can use the classic getframe / cdata idiom. With the figure window open, simply do this:
figure;
imshow(img); title('Output Image');
h = getframe;
im = h.cdata;
h is a handle to the current frame that is open, and the cdata field contains image data for the frame. The above code stores the frame image data into a variable called im for use for later.
Minor Comment
That for loop code to set the output is a bit inefficient. You can do this completely vectorized and you'll notice significant speedups.
This code:
for i=1:R
for j=1:C
if Bw(i,j)==1
img(i,j)=img(i,j);
else
img(i,j)=0;
end
end
end
... can be replaced with:
img(~BW) = 0;
I also don't understand why you'd need to store the image data inside the frame of imshow... when img already contains your data and you are ultimately showing the data contained in img. Why can't you just use img directly for your application? Nevertheless, the above solution will work.

Matlab: How can I display several outputs in the same image?

Let's say my image is img=zeros(100,100,3), my outputs are several ellipse which i get using a created function [ret]=draw_ellipse(x,y,a,b,angle,color,img), I can display one ellipse using imshow(ret).For the moment, I'm trying to show serval ellipse in the image. But i don't know how to code it. will ‘for loop’ work or I need to hold them?
If this is related to what you were doing in your previous question, then what you need to do is to pass the result of one iteration as input to the next.
So assuming that the function [ret]=draw_ellipse(x,y,a,b,angle,color,img) you mentioned takes as input an image img and returns the same image with an ellipse drawn on it, you could do this:
%# ellipses parameters
%#x = {..}; y = {..};
%#a = {..}; b = {..};
%#angle = {..}; color = {..};
img = zeros(200,100,'uint8'); %# image to start with
for i=1:10
img = draw_ellipse(x{i},y{i}, a{i},b{i}, angle{i}, color{i}, img);
end
imshow(img)
I'm a bit unsure of what you want. You want to show several ellipse in one image, like plotting several graphs with hold on?
There is no equivalent command for images, but a simple solution is to add the ellipses into one image and show that one:
several_ellipse = ellipse1 + ellipse2 + ellipse3;
imshow(several_ellipse)
Presumably you want to pass ret as the final input to the next call to draw_ellipse.

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