Transformation onto a fixed reference image

Hello,

I want to apply a transformation to an image using this imwarp function. It seems to be able to read all the inputs B = imwarp(A, tform). The input image is 1140x800. However, the output image has different dimensions. I want the transformed output image to also have the same dimensions as the input image (1140x800). Is there any way to do so?

Answer 1

[Matt J]

Yes, use the OutputView option like in htis example,

https://www.mathworks.com/help/images/ref/imwarp.html#mw_28861ab4-e9d2-4b5d-a068-adf687267aae

[Sakib Hossain]

Hey,

Thanks for your answer! However, our tform is in the form of a projective2d. When I try to run the code you mentioned, I get this error:

Error using affineOutputView>parseInputs (line 144)
The value of 'tform' is invalid. Expected tform to be one of these types:

affine2d, affine3d

Instead its type was projective2d.

Error in affineOutputView (line 57)
inputs = parseInputs(tform,sizeA,varargin{:});

Is there a similar function for a projective2d input? Just as a note, we are deriving the tform file from a fitgeotrans function (unsure if this provides an insights).

[Matt J]

I don't think there is a projective2dOutputView() utility, but you can always just use imref2d() to create your own OutputView specification.

[Sakib Hossain]

Hey Matt,

Thanks for your response. How would I set up the code using imref2d() for the centerOutput, followOutput, and sameAsInput under the imwarp function?

Ideally, all I need is to apply the transformation within a set bound of 1140x800. However, like I said before, once the transformation is applied, the output goes beyond these bounds. All the transformation are applied properly except for the translation/placement of the slice.