fenêtrage d'une image scannographie

si vous plait comment je peux appliquer un fenêtrage sur une image Dicom selon les paramètres de centre de la fenêtre et de largeur de la fenêtre voila les valeurs des paramètres (WL=40 WW=85)

Answer 1

[Image Analyst]

help conv2

 CONV2 Two dimensional convolution.
    C = CONV2(A, B) performs the 2-D convolution of matrices A and B.
    If [ma,na] = size(A), [mb,nb] = size(B), and [mc,nc] = size(C), then
    mc = max([ma+mb-1,ma,mb]) and nc = max([na+nb-1,na,nb]).
 
    C = CONV2(H1, H2, A) first convolves each column of A with the vector
    H1 and then convolves each row of the result with the vector H2.  If
    n1 = length(H1), n2 = length(H2), and [mc,nc] = size(C) then
    mc = max([ma+n1-1,ma,n1]) and nc = max([na+n2-1,na,n2]).
    CONV2(H1, H2, A) is equivalent to CONV2(H1(:)*H2(:).', A) up to
    round-off.
 
    C = CONV2(..., SHAPE) returns a subsection of the 2-D
    convolution with size specified by SHAPE:
      'full'  - (default) returns the full 2-D convolution,
      'same'  - returns the central part of the convolution
                that is the same size as A.
      'valid' - returns only those parts of the convolution
                that are computed without the zero-padded edges.
                size(C) = max([ma-max(0,mb-1),na-max(0,nb-1)],0).
 
    See also CONV, CONVN, FILTER2, XCORR2.
 
    Note: XCORR2 is in the Signal Processing Toolbox.

    Documentation for conv2
       doc conv2

    Other uses of conv2

       codistributed/conv2    gpuArray/conv2    tall/conv2

There are other windowed functions, for example stdfilt, imgaussfilt, etc.. It really depends on what you want to do with the pixels inside the window.

[rami]

Je veux lire des images scanographiques selon les paramètres de fenêtrage déjà définis dans dicominfo

[Image Analyst]

OK, then go ahead. Use dicomread and one of the functions I told you about.

[Med]

J'ai pas compris où je peux mettre les deux paramètres Wl et WW

[Image Analyst]

grayImage = dicomread(fileName);
WI = 40;
WW = 85;
filterWindow = ones(WI, WW);
outputImage = conv2(double(grayImage), filterWindow, 'same');
imshow(outputImage, []);

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[rami]

Je pense que la solution est similaire à ce code, mais il manque quelque chose.

info=dicominfo('1.2.156.14702.1.1000.16.2.20220802014611796000200030141');

image=int16(dicomread('1.2.156.14702.1.1000.16.2.20220802014611796000200030141'));

image=image.*info.RescaleSlope+info.RescaleIntercept;

MAX=max(image(:));

MIN=min(image(:));

value1=info.WindowCenter-floor(info.WindowWidth/2);

value2=info.WindowCenter+floor(info.WindowWidth/2);

me=(MAX-MIN)/(value2-value1);

b=MIN-(me*value1);

for i=1:length(image)

for j=1:width(image)

if image(j,i)>=value2

image(j,i)=MAX;

elseif image(j,i)<=value1

image(j,i)=MIN;

else

image(j,i)=me*image(j,i)+b;

end

end

end

figure,imshow(image,[])

[Image Analyst]

Don't use "image" as the name of your variable since it's the name of a built-in function.

Do not use the index j to loop over the width of the image. Since j is the column, not row, j should be the second index, not the first. Otherwise you'll get an index out of range error. Try this:

info = dicominfo('1.2.156.14702.1.1000.16.2.20220802014611796000200030141');
grayImage = int16(dicomread('1.2.156.14702.1.1000.16.2.20220802014611796000200030141'));
% Display image.
subplot(1, 2, 1);
imshow(grayImage,[])
axis('on', 'image');
impixelinfo
title('Original Image')

grayImage = grayImage.*info.RescaleSlope + info.RescaleIntercept;
maxGrayLevel = max(grayImage, 'all')
minGrayLevel = min(grayImage(:))
value1 = info.WindowCenter-floor(info.WindowWidth/2)
value2 = info.WindowCenter+floor(info.WindowWidth/2)
me = (maxGrayLevel-minGrayLevel) / (value2-value1)
b = minGrayLevel - (me * value1)
[rows, columns, numberOfColorChannels] = size(grayImage)

for row = 1 : rows
    for column = 1 : columns
        if grayImage(row, column)> = value2
            grayImage(row, column) = maxGrayLevel;
        elseif grayImage(row, column)<=value1
            grayImage(row, column) = minGrayLevel;
        else
            grayImage(row, column) = me*grayImage(row, column)+b;
        end
    end
end

% Display image.
subplot(1, 2, 2);
imshow(grayImage,[])
axis('on', 'image');
impixelinfo
title('Modified Image')