I have generated an array of processed data for each pixel in my image. I want to use the impixelinfo function to show the pixel information. However, it only shows the RGB value with respective x and y coordinates. How can I append the processed data into the info box?
Example of the RGB info box
Here is my answer:
imshow(uint8(image));
dcm_obj = datacursormode(gca);
set(dcm_obj,'UpdateFcn',{#myupdatefcn,image,other parameter});
function txt = myupdatefcn(empt,event_obj,image,other parameter)
pos = get(event_obj,'Position');
img = image(pos(2),pos(1),:);
txt = {['X:',num2str(pos(1)),' Y:',num2str(pos(2))],...
['R:',num2str(img(1,1,1)),' G:',num2str(img(1,1,2)),' B:',num2str(img(1,1,3))]
};
end
Related
I have a brain MRi image in .png format. I read the image and extract the K-Space and set some of the K-Space as 0
img_fft = fftshift(fft2(img));
sizes = size(img_fft);
row_half = sizes(1)/2;
flag = true;
for r = row_half:sizes(1)
for c = 1:sizes(2)
img_fft(r,c) = 0+1i*0;
end
end
After this I change the image back to image space using
img_back = ifft2(ifftshift(img_fft));
and after this I cast the image to uint8 as that was the original image format.
When I try to plot my image using imshow() I get a different output compared to when I write the image using imwrite. Also if I use abs(img_back) in imwrite I get an error.
Error using abs: Complex integers are not supported.
My plotting code is below:
img_back = ifft2(ifftshift(img_fft));
img_back = cast(img_back,'uint8');
subplot(1,3,1), imshow(img)
subplot(1,3,2), imshow(img_back)
subplot(1,3,3), imshow(abs(img_fft),[])
imwrite(abs(img_back),'back_img.png','png')
Can someone tell me what I am doing wrong here?
Take absolute value after inverse Fourier transform and then cast the result to uint8 type:
img_back = abs(ifft2(ifftshift(img_fft)));
img_back = cast(img_back,'uint8');
I am trying to concatenate two 256x256 images and save them using imwrite. The saved image is supposed to be 256x512, but when I load the saved image, the size shows to be 343x434x3. How do I solve this?
the code I am using is:
new_name3 = strcat(f_name_image, '\', kk, '_', num2str(ff), '_pair.png');
pair = [orig_im noisy_image]; %concatenating two 256x256 images
imagesc(pair)
f = getframe(gca);
im = frame2im(f);
imwrite(im, new_name3);
Saving the image from the frame can be lossy without configuring additional options. To retain the pixel information save the concatenated image directly from the pair (here Image_Pair) array. Also, the third dimension in 343x434x3 represents the RGB colour channels of the image.
%Grabbing the two images%
Image_1 = imread('Image_1.jpeg');
Image_2 = imread('Image_2.jpeg');
%The file name for the concantenated images%
New_File_Name = "Image_3.jpeg";
%Concatenating the images%
Image_Pair = [Image_1 Image_2];
%Displaying the image pair%
imshow(Image_Pair);
%Saving the image to the "New_File_Name"%
imwrite(Image_Pair, New_File_Name);
%Loading the saved image to see if dimensions are consistent%
Saved_Image = imread('Image_3.jpeg');
I am trying to use DIPimage to get some measurements of each object in an image and I get this error:
Error using dip_measure
DIPlib Error in function dip_Measure.
DIPlib Error in function dip_ImageCheck: Data type not supported
Error in measure (line 209)
data = dip_measure(object_in,gray_in,measurementID,objectIDs,connectivity);
Error in Untitled (line 13)
msr = measure(b, [], ({'size', 'perimeter','podczeckShapes'}))
How can I solve it?
Code:
Image = rgb2gray(imread('pillsetc.png'));
BW = imbinarize(Image);
BW = imfill(BW,'holes');
imshow(BW);
[B,L] = bwboundaries(BW,'noholes');
k = 1;
b = B{k};
y = b(:,2);
x = b(:,1);
msr(k) = measure(BW, [], ({'size', 'perimeter','podczeckShapes'}))
sz = msr.size;
podczeckShapes = podczeckShapes;
One problem with your code is the call to imfill. Because the image has bright values all around the image, it is considered that there's a large object with a hole, and your actual objects are inside this hole. imfill fills the hole, leaving the whole image white.
Instead, I suggest the following code to remove the frame:
Image = rgb2gray(imread('https://i.stack.imgur.com/fmqAF.jpg'));
BW = imbinarize(Image);
BW = BW - bpropagation(false(size(BW)), BW);
Because we used a filter in DIPimage, the BW variable now contains a dip_image object, not a normal MATLAB array. dip_array(BW) extracts the normal MATLAB array that is inside. The dip_image object behaves differently from a MATLAB array. For example, you can display it to an interactive figure window by just typing its name:
BW
Next, we apply labeling so that we know which object ID in the measurement data corresponds to which object:
lab = label(BW);
dipshow(lab,'labels')
Now we can apply the measurement function. If we use BW as input, label will be called on it. Since we already have that result, let's use it directly:
msr = measure(lab, [], {'size', 'perimeter','podczeckShapes'});
Let's examine results for object ID 8, which is the large square:
sz = msr(8).size
square = msr(8).podczeckShapes(1)
triangle = msr(8).podczeckShapes(3)
There are other things you can do with the measurement structure, I suggest you read the documentation. For example, we can remove from it the measurement for the littlest objects, which to me look like noise:
msr = msr(msr.size>100); % remove measurement for noise
I have a set of .raw depth images. The image format is 500X290 with 32 bytes per pixel. When I open them with IrfanView image viewer I see the depth image correctly like this:
displayed image in IrfanView
Now I want to read and display the same depth image in Matlab. I do like this:
FID=fopen('depthImage.raw','r');
DepthImage = fread(FID,[290,500],'bit32');
fclose(FID);
colormap winter;
imshow(DepthImage);
DepthImage is a 290X500 type double matrix.
what I get from this code is this image:
displayed image in Matlab viewer
when I change fread parameter from 'bit32' to 'bit24' I get this:
displayed image in Matlab with bit24
I guess each element in DepthImage contains 32 bits where each 8 bits corresponds to R,G,B and D values. but how can I read the image correctly and display it like the one in IrfanView?
the raw file: https://drive.google.com/file/d/1aHcRmMKvi5gtodahR5l_Dx8SbK_920c5/view?usp=sharing
There might be an issue with image metadata header, like "date and time of the shot", "camera type". Open your image with notepad++ to check for "date and time". If you upload your original raw image, it will be easier to try things.
Upd: Ok, this is something. Check if it helps
FID=fopen('camera00000000000014167000.raw','r');
DepthImage = fread(FID,290*500*4,'int8');
DepthImageR = DepthImage(1:4:end);
DepthImageG = DepthImage(2:4:end);
DepthImageB = DepthImage(3:4:end);
DepthImageD = DepthImage(4:4:end);
dataR = reshape(DepthImageR, 500,290);
dataG = reshape(DepthImageG, 500,290);
dataB = reshape(DepthImageB, 500,290);
dataD = reshape(DepthImageD, 500,290); % all equal to 64 - useless
figure()
subplot(2,2,1)
image(dataR)
subplot(2,2,2)
image(dataG)
subplot(2,2,3)
image(dataB)
subplot(2,2,4)
data = zeros(500,290,3);
data(:,:,1) = dataR;
data(:,:,2) = dataG;
data(:,:,3) = dataB;
image(data)
I'm reading in a Tiff using the below function, which works fine, but when I try to use my write function to write that same Tiff back to a different file, it's all 255's. Does anyone know how to fix this? Thanks, Alex.
function Y = tiff_read(name)
% tiff reader that works
info = imfinfo(name);
T = numel(info);
d1 = info(1).Height;
d2 = info(1).Width;
Y = zeros(d1,d2,T);
for t = 1:T
temp = imread(name, t, 'Info',info);
Y(:,:,t) = temp(1:end,1:end);
end
% Tiff writer that doesn't work
function tiff_write(Y,name)
% Y should be 3D, name should end in .tif
T = size(Y,3);
imwrite(Y(:,:,1),name);
for t = 2:T
imwrite(Y(:,:,t),name,'WriteMode','append');
end
Try using this line :
Y = zeros(d1,d2,T,'uint16');
instead of this one:
Y = zeros(d1,d2,T);
Your data are likely in uint16 format and when you export you clip the maximum value to 255 (uint8), which makes pixel with values greater than 255 (a LOT of them if your data is in uint16) appear white.
Otherwise you might want to use this line:
function tiff_write(Y,name)
% Y should be 3D, name should end in .tif
for t = 2:T
imwrite(Y(:,:,t)/255,name,'WriteMode','append');
end