three.js/examples/js/shaders/GammaCorrectionShader.js

( function () {

	/**
 * Gamma Correction Shader
 * http://en.wikipedia.org/wiki/gamma_correction
 */
	var GammaCorrectionShader = {
		uniforms: {
			'tDiffuse': {
				value: null
			}
		},
		vertexShader: [ 'varying vec2 vUv;', 'void main() {', '	vUv = uv;', '	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );', '}' ].join( '\n' ),
		fragmentShader: [ 'uniform sampler2D tDiffuse;', 'varying vec2 vUv;', 'void main() {', '	vec4 tex = texture2D( tDiffuse, vUv );', '	gl_FragColor = LinearTosRGB( tex );', // optional: LinearToGamma( tex, float( GAMMA_FACTOR ) );
			'}' ].join( '\n' )
	};

	THREE.GammaCorrectionShader = GammaCorrectionShader;

} )();