How to resize a 3D image

Hi, I’m trying to resize a 3D image to an specific size, but I’m getting as a result a white image with some black slices.

Here is the code:

sitk::Image imResize3(sitk::Image input, sitk::Image output_size_image)
    std::vector<unsigned int> new_dims = output_size_image.GetSize();
    std::vector<unsigned int> old_dims = input.GetSize();

    sitk::AffineTransform affine = sitk::AffineTransform(3);
    std::vector<double> affine_matrix = affine.GetMatrix();
    affine_matrix[0] = new_dims[0]/old_dims[0];
    affine_matrix[4] = new_dims[1]/old_dims[1];
    affine_matrix[8] = new_dims[2]/old_dims[2];

    sitk::Image resampled_image = sitk::Resample(input, output_size_image, affine, sitk::sitkBSplineResamplerOrder3);
    return resampled_image;

The function receives the input image, which the user wants to resize, and the output image, which has the target size. The input image has the size: 256x256x26 and the output image has 182x218x182. Both images have spacing of 1.

Here is the input image.

Here is the output image.

So, how can I solve this problem?

Thank you.

You should not modify the scale of the transform, you want identity transform. What you need to modify is the size and spacing of the output_size_image. Also take a look at a previous discussion:

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