I'm trying to convert a function I use in MATLAB to merge an RGB image with an IR image (both in JPG formats) to create a Tiff image with 4 bands (R, G, B, IR). However, I have some problem implementing the Tiff function, as it looks like that Tiff is not implemented in Octave.
Someone know how can I convert the Tiff part of following function to Octave?
for fidx = 1:numel(filelist1)
rgb = imread(fullfile(folder1, filelist1{fidx}));
numrows = size(rgb,1);
numcols = size(rgb,2);
ir = imread(fullfile(folder2, filelist2{fidx}));
data = cat(3,rgb,ir);
t = Tiff(fullfile(folderout, sprintf(outfilepattern, fidx))','w');
setTag(t,'Photometric',Tiff.Photometric.RGB);
setTag(t,'Compression',Tiff.Compression.None);
setTag(t,'BitsPerSample',8);
setTag(t,'SamplesPerPixel',4);
setTag(t,'SampleFormat',Tiff.SampleFormat.UInt);
setTag(t,'ExtraSamples',Tiff.ExtraSamples.Unspecified);
setTag(t,'ImageLength',numrows);
setTag(t,'ImageWidth',numcols);
setTag(t,'TileLength',32);
setTag(t,'TileWidth',32);
setTag(t,'PlanarConfiguration',Tiff.PlanarConfiguration.Chunky);
write(t,data);
close(t);
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 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 have an nCol by nRow matrix of doubles that I want to convert into an nCol by nRow grayscale images of pixels. I don't want to cut this down to an image scaled to 256 channels. I'd be happy with using singles instead of doubles. I've looked through the Tiff class documentation from Mathworks but can't find a simple example for this.
I tried to read about Tiff class and yep it is very poor documented. But I found this going through trial and error:
lets say we have matrix
data = rand(100,200);
Lets save it as Tiff:
t = Tiff('new.tif','w') %create object of Tiff class
setTag(t,Tiff.TagID.ImageLength,size(data,1)) %define image dimentions
setTag(t,Tiff.TagID.ImageWidth,size(data,2))
setTag(t,'Photometric', Tiff.Photometric.MinIsBlack) %define the color type of image
%specifies how image data components are stored on disk
setTag(t,'PlanarConfiguration',Tiff.PlanarConfiguration.Chunky);
setTag(t,'BitsPerSample',64); %because 1 double = 8byte = 64bits
%Specify how to interpret each pixel sample (IEEEFP works with input doubles)
setTag(t,'SampleFormat',Tiff.SampleFormat.IEEEFP);
t.write(data)
t.close
Lets test this now:
datac = imread('new.tif')
whos datac
Name Size Bytes Class Attributes
datac 100x200 160000 double
And:
datac(:,1)
ans =
0.4921
0.6908
0.1544
0.4433
...
I have an RGB image which I converted into index image using rgb2index. The resultant image is stored in two variable (as matlab requirement). But I want to have it in one variable for further processing. This is what I have tried. The resultant is black.
clc
clear all
close all
%%
I = imread ('Daniel1_SRGB.png');
[in_I,map] = rgb2ind(I,3,'nodither');
imshow (in_I,map)
imwrite (in_I,map,'new_image.PNG','png')
new_I = imread ('new_image.png');
imshow((new_image));
But if do imshow((new_image,map)) it gives me the correct answer. I want it to be independent of variable map.
To convert a indexed image to RGB use:
new_I = ind2rgb(in_I,map)
Not the most elegant solution but this works.
resR = reshape(map(in_I(:)+1,1), size(in_I));
resG = reshape(map(in_I(:)+1,2), size(in_I));
resB = reshape(map(in_I(:)+1,3), size(in_I));
res = cat(3, resR, resG, resB);
imshow(res);
Edit: Modified answer to include rayryeng's improvement.