Arbitrary geometric transformation filter

[DrPepperJo]

Hi guys,

I am looking for a way to apply an arbitrary geometric transformation to a image / smart object. Say I have a formula like

point_source = var_1 + var_2 * point_destination

to specify how a point in the resulting destination image is mapped to a point location to be sampled in the source image. I would want a way to apply such a formula while providing the variables (var_1 and var_2) via some kind of script, input field or file.

Photoshop seems to have a number of dedicated geometric filters like "Adaptive Wide Angle" or "Lens Correction", but I couldn't find a way to apply a arbitrary mapping formula. I'm a software developer, so if there is no "out of the box" solution to this, I'd greatly appreciate pointing me to the best way to achieve this using the Photoshop scripting / plugin interfaces.

Cheers,
Jo

[JJMack]

Are you going to be creating the smart objects in the document from a raster image layer.  If you are not and the document has a smart object layer for the image you script will need to retrieve the object current transform and warping settings to see the layer's image current state.

[DrPepperJo]

Thanks for the hint. Since I will be the only one using this, I will make sure that I start with a "clean" smart object created from an image.

[Semaphoric]

That is pretty much what Filter > Distort > Displace does. It uses a Displacement Map, which is stored in the first two channels of a Photoshop "Maximize Compatiblity" composite.

I have never tried scripting it, but I did cobble together a Basic program that constructed a D-map which emulated the Sphereize filter.

If you don't need perfect numerical precision, you can construct on with diverse methods, like the Emboss filter, or applying Curves to a Black-White gradient. With the latter, you can inject formulas back into the mix with Davide Barranca's Parametric Curves plugin.