CODEWITHSUNDEEP
webgl
tzador
tzador

Reputation: 2641

Getting data out of webgl

I am interested in performing some intensive calculations in webgl, so its run on GPU.

Most of the docs speak about how render graphics though.

I am after very simple task: for given image, transform it to grayscale, and find coordinates of local maxima (pixels that are brighter than its neighbours).

I would like to run the 'loops' in webgl shader, but getting out the (x, y) of the local maxima pixels to the javascript world. Is it doable? Whats the best way to do it, so that it performs well by processing pixels in parallel?

Upvotes: 2

Views: 789

Answers (1)

JAre
JAre

Reputation: 4756

You can render full-screen quad with shader that sample pixels from your texture(image) in some square(like 4x4 or 16x16 resolution limited by maximal amount of texture samples) and output maximal value as fragment color + maximal pixel texture coordinate(if needed) to the lower resolution texture. So you will have reduced image. You can iterate this to achieve global maximum.

Read this http://www.lcg.ufrj.br/Cursos/GPUProg/GPGPU_Reductions

Upvotes: 3

Related Questions