import {brightnessContrast} from '@luma.gl/effects';
import {PostProcessEffect} from '@deck.gl/core';

const postProcessEffect = new PostProcessEffect(brightnessContrast, {
  brightness: 1.0,
  contrast: 1.0
});

const deckgl = new Deck({
  canvas: 'my-deck-canvas',
  initialViewState,
  controller: true,
  // add effect to deck
  effects: [postProcessEffect],
  layers: [new GeoJsonLayer({
    ...
  })]
});