是否可以在不调整图像大小的情况下在 MATLAB 中使用插值？

Question

我有一个图像，其中一些像素被故意更改为零。现在我想进行双线性插值，以使用邻域来找出新的像素值，就像双线性插值一样。但是，我不想调整图像大小（MATLAB 只能使用 resize 函数进行双线性插值）。

是否可以在不调整大小的情况下在 MATLAB 中进行双线性插值？我读到与双线性核的卷积可以解决这个问题。你知道这是哪个内核吗？有可能做我想做的事吗？

Answer 1

您可以尝试使用griddata支持的选项之一：

griddata(..., METHOD) where METHOD is one of
    'nearest'   - Nearest neighbor interpolation
    'linear'    - Linear interpolation (default)
    'natural'   - Natural neighbor interpolation
    'cubic'     - Cubic interpolation (2D only)
    'v4'        - MATLAB 4 griddata method (2D only)
defines the interpolation method. The 'nearest' and 'linear' methods 
have discontinuities in the zero-th and first derivatives respectively, 
while the 'cubic' and 'v4' methods produce smooth surfaces.  All the 
methods except 'v4' are based on a Delaunay triangulation of the data.

示例

% create sample data
[X, Y] = meshgrid(1:10, 1:10);
Z_original = X.*Y;

% remove a data point
Z_distorted = Z_original;
Z_distorted(5, 5) = nan;

% reconstruct
valid = ~isnan(Z_distorted);
Z_reconstructed = Z_distorted;
Z_reconstructed(~valid) = griddata(X(valid),Y(valid),Z_distorted(valid),X(~valid),Y(~valid));

% plot the result
figure
surface(Z_original);

figure
surface(Z_distorted);

figure
surface(Z_reconstructed);