Image with Horizontal Longitudinal View
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Hi. I'm new in image processing. I have a multi frame image which consist of 271 frames . and i want to cut each slice to get longitudinal view as shown in attached figure. I have the upper portion of image . and want to get lower view . any one please help me
4 个评论
Guillaume
2018-4-26
How is the multiframe image stored in matlab? A 4D array (height x width x RGB x frame)?
Arsalan Akbar
2018-4-26
编辑：Arsalan Akbar
2018-4-26
Walter Roberson
2018-4-26
Please recheck the bounds and sizes. 0 to 271 is 272 different values. 0 to 360 is 361 different values.
When the slicing is done, is the location to be specified as an index, or is it to be specified by value that might not happen to correspond exactly to an index? If it is by value that might be between the locations of two stored locations, then should the nearest location be taken or should linear interpolation be used to blend the adjacent locations?
Arsalan Akbar
2018-4-26
采纳的回答
Guillaume
2018-4-26
If I understood correctly. The multiframe image is greyscale or indexed, since each image is 2D, and the frame are the pages of a 3D matrix. From that you want a slice of each frame, a single column of each image, concatenated together horizontally as a single image. If so:
sliceimage = permute(yourmultiframeimage(:, slicecolumn, :), [1 3 2]);
18 个评论
Arsalan Akbar
2018-4-26
Arsalan Akbar
2018-4-26
Arsalan Akbar
2018-4-26
Walter Roberson
2018-4-26
%going in reverse order effectively takes care of pre-allocation
for K = 271:-1:1;
yourmultiframeimage(:,:,:,K) = imread(sprintf('%d.tif',K));
end
slicecolumn = 173;
sliceimage = permute(yourmultiframeimage(:, slicecolumn, :), [1 3 2]);
image(sliceimage);
colormap(gray(256));
Looks okay to me on the 10-image subset you provided.
Arsalan Akbar
2018-4-27
Walter Roberson
2018-4-27
slicerow = 57;
sliceimage_x = permute(yourmultiframeimage(slicerow, :, :), [2 3 1]);
image(sliceimage_x);
colormap(gray(256));
Arsalan Akbar
2018-4-28
Walter Roberson
2018-4-28
Use interp3() with y = m*(x-xc)+yc and m = tand(angle) (but watch out for vertical) . You might want to have a look at the improfile() source code to see how it calculates which intermediate points to sample at.
Guillaume
2018-4-28
I assume you're capable of calculating the coordinates of the end points of the line segment going through the image at whichever angle you want. E.g, for 45° (for a square image),
x = [1, size(yourmultiframeimage, 2)];
y = [1, size(yourmultiframeimage, 1)];
Then the simplest thing is to ask improfile for the coordinates of the pixels in between, then use that to extract the pixels of each frame:
[linex, liney, ~] = improfile(yourmultiframeimage(:, :, 1), x, y);
sliceimage = yourmultiframeimage(sub2ind(size(yourmultiframeimage), ...
repmat(round(liney), 1, size(yourmultiframeimage, 3)), ...
repmat(round(linex), 1, size(yourmultiframeimage, 3)), ...
repmat(1:size(yourmultiframeimage, 3), numel(linex), 1)));
Arsalan Akbar
2018-4-30
Guillaume
2018-4-30
Who are you replying to and what does I'm not able to get your point actually mean?
Arsalan Akbar
2018-4-30
Arsalan Akbar
2018-5-1
Guillaume
2018-5-1
I'm not able to calculate the endpoints of a line segments at certain angle
Seriously? It's elementary math. Do put in some effort
%angle: angle in degree, clockwise from vertical
xcentre = floor(size(yourimage, 2) / 2);
ycentre = floor(size(yourimage, 1) / 2);
xtop = xcentre + ycentre / tan(angle);
yright = ycentre - (size(yourimage, 2) - xcentre) * tan(angle);
xbottom = xcentre - (size(yourimage, 1) - ycentre) / tan(angle);
yleft = ycentre + xcentre * tan(angle);
if xtop < 0 | xtop > size(yourimage, 2)
x = [1, size(yourimage, 2)];
y = [yright, yleft];
else
x = [xbottom, xtop];
y = [size(yourimage, 1), 1];
end
Arsalan Akbar
2018-5-3
Guillaume
2018-5-3
In the very first line of my answer, I wrote: "If I understood correctly, the multiframe image is greyscale or indexed". (i.e. each frame is 2D and the multiframe image is 3D). All my answers were written with that assumption.
From your code, it looks like each frame is RGB (3D), which means the answer you accepted wouldn't have worked unless you converted the frame to greyscale. If so, do the same for the other angles.
Arsalan Akbar
2018-5-3
Arsalan Akbar
2018-5-3
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