We developed a method to make a synthetic lenslet image from a synthetic light field.
We first remove some peripheral views (in the corners), in order to have circular angular patches (as the captured plenoptic light field are).
Then we put the different angular patches near one another along a hexagonal grid. This operation is the exact contrary of the slicing or demultiplexing step in the decoding pipeline.
We also add vignetting to the lenslets and generate a white image that holds the exact vignetting profile of the lenslet image (dividing the lenslet image by the white image will give us perfect devignetting).
White image guided demosaicing algorithm
We propose to discard the pixels that are out of the lenslets from the demosaicing step.
To do this, we adapted the gradient corrected interpolation method by weighting the bilinear interpolation and gradient correction:
- First with a mask (b): we do not want to interpolate data from different lenslets as this creates crosstalk artifacts. Knowing the lenslet grid parameters, we know the position of the lenslets centers and we can identify the pixels which belong to the same lenslets.
- Then with a white image (c): we have full confidence in the pixels that have the maximum values on the white image whereas we have less confidence in the pixels that are darker on the white image, as they are noisier.
Results with synthetic and real light fields