插值算法值均为255 -MATLAB

Question

我尝试在Matlab中建立自己的最近邻插值算法，将556×612到1668×1836的图像放大。

这是作业！

我已经尝试过了，但是遇到了这样的错误:M中的值被转换成255 (空白)(不是全部，而是大多数)，我无法理解为什么。任何帮助都将不胜感激！这是一张斑马的照片。

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    %Take in image and convert to greyscale
I = imread('Zebra.jpg');
Igray = rgb2gray(I);

% Step-3: Resize the image to enlarged 1668x1836 by interpolation
% Step-3(a) : Using nearest neighbour
%First we will need to work out the dimension of the image
[j , k] = size(Igray);
%Now we need to set the size of the image we want
NewX = 1836;
NewY = 1668;
% Work out ratio of old to new
ScaleX = NewX./(j-1);
ScaleY = NewY./(k-1);

%Image Buffer
M = zeros(NewX, NewY);
%Create output image
for count1 = 1:NewX
    for count2 = 1:NewY
        M(count1,count2) = Igray(1+round(count1./ScaleX),1+round(count2./ScaleY));
    end
end
%Show Images
imshow(M);
title('Scaled Image NN');

Answer 1

试试imshow(M,[])。您创建了M，而没有指定类型，这使得它成为double。double图像为0- 1，因此默认情况下，imshow使所有值高于1的事物变为白色。

或者，将M创建为uint8作为原始图像

M = zeros(NewX, NewY,'uint8');

更好的代码是：

M = zeros(NewX, NewY,class(Igray));