MATLAB combine two avi. together - matlab

I created two avi. file and they have the same length.
I wanted to combine them on a same background and one on top another one on the bottom.
The code I used for one of the animation is below, the other one is similar.
Is there any way I can do that?
load Results.mat;
I = imread('hex08.jpg');
[rows,columns,numberOfColorChannels] = size(I);
if numberOfColorChannels >1
I = I(:,:,2);
end
background = imresize(background, [rows,columns]);
figure(1);
hold on;
for i=1:500
A=angle(i,:);
J = imrotate(I,A,'crop');
mask = J == 0;
mask = bwareafilt(mask,4);
J(mask) = background(mask);
pause(0.01)
imshow(J);
imwrite(J,[num2str(i),'.png']);
end
imageNames = dir(fullfile('*.png'));
imageNames = {imageNames.name}';
outputVideo = VideoWriter(fullfile('hex08.avi'));
outputVideo.FrameRate = 15;
open(outputVideo)
for ii = 1:length(imageNames)
img = imread(fullfile(imageNames{ii}));
writeVideo(outputVideo,img)
end
close(outputVideo)

Here is one way this can be done:
Just like you read the image into img, you can read a second image (from the second video) into img2. Then, you can create a combined image of the two: imgCombined = [img ; img2]; which will contain the first image on top and the second on bottom (This will work if both images are the same width, otherwise you will need to resize/crop). When you write to the video file, use writeVideo(outputVideo,imgCombined).

Related

Spheroids detction from Images

I need to find the blobs from the below image.
The major problem is background. background doesn't have uniform intensity. I tried couple of things like thresholding and edge detection in MATLAB but couldn't able to find a better ways to segment out all spheroids. I need to extract the blobs and I need to find the area of each blobs. Does anyone know how to work-around with this kind of background?
Edit (07/02/17):
As suggested by Spektre I tried Following things in MATLAB.
Method 1:
img_original = imread('~/my_image.jpg'); %Read image
img_ch = single(img_original(:,:,2)); %Pick one channel( here its green)
g = fspecial('gaussian',200,100); %Kernel matrix to make the img blurr
con_img = conv2(img_ch,g,'same'); %2D convolution, this wil make the img blurr
sub_img = (con_img - img_ch); %Simple matrix subtraction
sub_img(sub_img <= 10) = 0; %Thresholding
sub_img(sub_img ~= 0) = 1;
fil_sub = imfill(sub_img,'holes'); %Fill the regions
imgfilt = imfilter(fil_sub, ones(3)); %run filter using 3by3 matrx
imgfilt(imgfilt < 8) = 0; %Reduce noisy pixels by thresholding
mfilt_img = (medfilt2(imgfilt)); %reduce unwanted pixels
img = img_ch;
img(mfilt_img ~= 0) = 255;
img2 = img_ch;
img2(img2 < 70) = 0; %Threshold for darker pixels which are left out from above methode.
img(img2 ==0) = 255;
disp_img = img_original(:,:,1);
disp_img(img ==255) = 255;
img_original(:,:,1) = disp_img;
figure, imshow(img_original)
I got the segments but still not good enough I think. This method gave good segments in the high intensity background, Even if I reduce the threshold value segments are not clear in the darker background and brightest pixels in the blobs are excluded.
Method 2:
img_original = imread('~/cancer_cells/Snap-10234.jpg'); %Read image
img_ch = single(img_original(:,:,2)); %Pick one channel( here its green)
clear new_matcel cur_img matcel avg_matrx
s=3; % Set size of the square window
mat_img = img_ch; % Working image channel
% resize the working matrix so that the dimensions matches
resize_img = resizem(mat_img,round(size(mat_img)/s)*s);
% convert matrix into small s x s matrix and save each in cells
window_c = ones(1,size(resize_img,1)/s) * s;
window_r = ones(1,size(resize_img,2)/s) * s;
mat_cel = mat2cell(resize_img,window_c,window_r);
new_matcel = cell(size(mat_cel)); % initialize new variable
% get the average value for each window and replace the actual by avg value
for i = 1:size(mat_cel,1)
for j = 1:size(mat_cel,2)
cur_img = mat_cel{i,j};
avg_value = mean(mean(cur_img));
new_matcel{i,j} = ones(s) * avg_value;
end
end
avg_matrx = cell2mat(new_matcel); % convert cells to matrix
image_sub = (abs(resize_img - avg_matrx)); % take the absolute difference
image_sub(image_sub < 7) = 0; % thresholding
image_sub(image_sub~=0) = 1;
image_sub = bwmorph(image_sub,'bridge');% fill gaps
image_sub = imfill(image_sub,'holes'); % fill the bounded regioons
% image_sub(image_sub == 1) = 255;
image_sub = resizem(image_sub,size(img_ch)); % resize to original size
disp_img = img_original(:,:,1);
disp_img(image_sub == 1) = 255;
img_original(:,:,1) = disp_img;
figure, imshow(img_original)
Much better segmented image:
even brighter pixels are included in the segment. Thanks to Spektre.
Is there a way to improve the above code? or any other idea to get more precise segments?
Thanks.

Saving a series of manually selected points

Just a quick question. I have generated a piece of code whereby I select the point of interest in every frame. However, the coordinates of the last selected point is the only one that is saved. Does anyone know how to set up the code such that all the points for each frame are saved for example in a text file with x position in column 1 and y position in column 2? Here is the code I have developed so far;
clear;
clc;
%% Video file information
obj = VideoReader('T9_720p_60p_60mm_f5.MOV');
%% Sampling rate
fps = get(obj, 'FrameRate');
dt = 1/fps;
%% Image Information
file_info = get(obj);
image_width = file_info.Width;
image_height = file_info.Height;
%%Desired image size
x_range = 1:image_height;
y_range = 1:image_width;
szx = length(x_range);
szy = length(y_range);
%%Image processing - Point selection
for n = 33:115
frame = read(obj,n);
imshow(frame);
hpoint = impoint(gca, []);
Position = getPosition(hpoint);
end
I just realized all I need was to add the following before the end of the loop
%%Save data
n = n-32;
data(n,:) = [Position];
end
Regards

How to convert rgb to gray but keep one colour unchanged

I have an image in which I want to only keep the green part and convert the others to gray scale.
It seems from the colors in your image, that the greens are actually so close to grayscale that you'll be unable to see anything. Either way this is how you do it:
im = imread('houses.jpg');
s= (im(:,:,2)>im(:,:,1))&(im(:,:,2)>im(:,:,3));
dim = double(im);
r = abs(dim(:,:,2)-((dim(:,:,1))+dim(:,:,2)+dim(:,:,3))/3) < 3;
q = s|r;
imgs = rgb2gray(im);
imgs3(:,:,1) = imgs;
imgs3(:,:,2) = imgs;
imgs3(:,:,3) = imgs;
imout = zeros(size(im));
for i=1:size(im,1),
for j=1:size(im,2),
if q(i,j) == 0,
imout(i,j,:) = imgs3(i,j,:);
else,
imout(i,j,:) = im(i,j,:);
end
end
end
imshow(uint8(imout))
imwrite(uint8(imout),'output.jpg');
if you want to see something useful you would probably want to do the following
im = imread('houses.jpg');
s= (im(:,:,2)>im(:,:,1))&(im(:,:,2)>im(:,:,3));
dim = double(im);
r = abs(dim(:,:,2)-((dim(:,:,1))+dim(:,:,2)+dim(:,:,3))/3) < 3;
q = s|r;
imgs = rgb2gray(im);
imgs3(:,:,1) = imgs;
imgs3(:,:,2) = imgs;
imgs3(:,:,3) = imgs;
imout = zeros(size(im));
for i=1:size(im,1),
for j=1:size(im,2),
if q(i,j) == 0,
imout(i,j,:) = imgs3(i,j,:);
else,
imout(i,j,1) = im(i,j,1);
imout(i,j,2) = 255;
imout(i,j,3) = im(i,j,3);
end
end
end
imshow(uint8(imout))
imwrite(uint8(imout),'output.jpg');
which gives this as result:
It should be something like this:
gray_img = rgb2gray(img);
green_mask = img(:,:,2) > img(:,:,1) & img(:,:,2) > img(:,:,3);
gray_img3 = cat(3, gray_img, gray_img, gray_img);
green_mask3 = cat(3, green_mask, green_mask, green_mask);
output_img = gray_img3;
output_img(green_mask3) = img(green_mask3);
I didn't check it, but I'm quite sure it should do the work.
The only thing you might want to modify is the computation of the mask, currently it will include all pixels that are more green than red or blue, but you may want to be more (or less) specific in choosing which pixels to leave unchanged.
I would suggest to use a purely hue=based approach, as you are interested in a specific color.
My approach would be to convert your images to the HSV colorspace and check the Hue channel.
img=imread('houses.jpg');
hsv=rgb2hsv(img);
% find the white areas of the image
gray_part=hsv(:,:,3)>0.7;
% find the green areas of the image that are not white
green_part=hsv(:,:,1)>(30/360) & hsv(:,:,1)<(210/360) & ~gray_part;
% create the output image
outimg=(uint8(double(img).*repmat(green_part,[1 1 3])));
figure;
subplot(121); imshow(img);
subplot(122); imshow(outimg);
This will give you the following image (left: original, right: resulting masked image):
Of course, if you need to get the rest of the image in grayscale you may use the previous results as follows:
pixel(1,1,1)=0;pixel(1,1,2)=255;pixel(1,1,3)=0;
green_img=repmat(pixel,[size(img,1) size(img,2), 1]);
green_part=repmat(green_part,[1 1 3]);
gray_img=rgb2gray(uint8(double(img).*~green_part));
gray_img=double(repmat(gray_img,[1 1 3]));
outimg=uint8(green_part.*green_img + gray_img);
figure; imshow(outimg);
This will display the image shown below:

MATLAB: Print contents of uipanel to PNG image

I don't know how to accomplish the following in MATLAB. I have a figure which looks like this:
In the figure, I have a panel with many subplots and a scrollbar that allows me to view a portion of the panel.
I want to save the whole contents of the panel to a PNG image file (not just the visible portion), i.e. I want to have a file which is a tall rectangle, and doesn't require scrolling.
The code for generating the figure is as follows:
function draw(obj)
figure;
panel1 = uipanel('Parent',1);
panel2 = uipanel('Parent',panel1);
panelheight = obj.nIterations / 2;
set(panel1,'Position',[0 0 0.97 1]);
set(panel2,'Position',[0 1-panelheight 1 panelheight]); %%
nPlot = 1;
for i=1:obj.nIterations
models = obj.iterations{i};
for nModel=1:length(models)
subplot(obj.nIterations,length(models)*2,nPlot);
nPlot = nPlot + 1;
drawTransitions(models{nModel});
set(gca,'Parent',panel2);
subplot(obj.nIterations,length(models)*2,nPlot);
nPlot = nPlot + 1;
drawRewards(models{nModel});
set(gca,'Parent',panel2);
end
end
s = uicontrol('Style','Slider','Parent',1,...
'Units','normalized','Position',[0.97 0 0.03 1],...
'Value',1,'Callback',{#slider_callback1,panel2,panelheight});
end
I have tried the following, without success.
The saveas funstion saves the whole figure, not just the panel. Also, it clips the invisible portion of the panel.
export_fig(panel2.'file.png') gives just a solid gray image.
Why don't you just scroll your panel and grab the frames and concatenate them all together? Here's some code that will basically do that. I would have posted am image, but I guess I don't have enough points for that. You may need to fiddle with the scrolling, and maybe making the slider invisible, but it works.
function printPanel(pnl,filename)
fig = figure(ancestor(pnl,'figure'));
pnl_units = get(pnl,'units');
fig_units = get(fig,'units');
set(pnl,'units','pixels')
set(fig,'units','pixels')
pnl_rect = getpixelposition(pnl);
fig_rect = getpixelposition(fig);
pnl_height = pnl_rect(4);
fig_height = fig_rect(4);
pnl_rect(2) = -pnl_height;
set(pnl,'position',pnl_rect)
N = ceil(pnl_height/fig_height);
CDATA = cell(N,1);
for i = 1:N
F = getframe(fig);
CDATA{i} = F.cdata;
pnl_rect(2) = pnl_rect(2)+fig_height;
set(pnl,'position',pnl_rect)
drawnow
end
set(pnl,'units',pnl_units)
set(fig,'units',fig_units)
imwrite(cat(1,CDATA{:}),filename)
end
You could get rid of the ui elements and just make a figure with all the subplots, and then export that one, using e.g. print -dpng ....
saveas takes a handle as a first argument. Maybe this does not have to be a figure or model handle, but could be a reference to the contents of the panel.

N-th largest component of bwconncomp including the background

My question has two parts. First one is:
How can I include the background as a component in the bwconncomp function, because it's default behavior doesn't include it.
Also, and this is my other question is, how can I select the n-th largest component based on what I get by using bwconncomp.
Currently I was thinking about something like this, but that doesn't work :P
function out = getComponent(im,n)
CC = bwconncomp(im,4);
%image is an binary image here
numPixels = cellfun(#numel,CC.PixelIdxList);
sortedPixels = sort(numPixels,'descend');
w = sortedPixels(n);
[largest, index] = find(numPixels==w);
im(CC.PixelIdxList{index}) = 0;
out = im;
But that doesn't work at all. But im not too sure what the CC.PixelIdxList{index} does, is it just changing elements in the array. I also find it kinda vague what exactly PixelIdxList is.
To find the background, you can use 'not' operation on the image
'PixelIdxList' is not what you need. You need the 'Area' property.
function FindBackgroundAndLargestBlob
x = imread('peppers.png');
I = x(:,:,2);
level = graythresh(I);
bw = im2bw(I,level);
b = bwlabel(bw,8);
rp = regionprops(b,'Area','PixelIdxList');
areas = [rp.Area];
[unused,indexOfMax] = max(areas);
disp(indexOfMax);
end
Update:
You can do it with bwconncomp as well:
function FindBackgroundAndLargestBlob
x = imread('peppers.png');
I = x(:,:,2);
level = graythresh(I);
bw = im2bw(I,level);
c = bwconncomp(bw,4);
numOfPixels = cellfun(#numel,c.PixelIdxList);
[unused,indexOfMax] = max(numOfPixels);
figure;imshow(bw);
bw( c.PixelIdxList{indexOfMax} ) = 0;
figure;imshow(bw);
end
Which will give the following results: