EMAGE

EMAGE is a webgl based image processing library, it is based on the webgl library qtek.

The example

Simple Usage

Import the library

<script type="https://github.com/pissang/emage/blob/master/dist/emage.min.js"></script>

Or in the AMD environment

var emage =	require("emage")

Process the image

	// Create a image processor
	var processor = new emage.Processor(canvas, image);
	
	// Create a layer
	var blurLayer = new emage.Layer();	
	
	// Use gaussian blur
	blurLayer.use("buildin.gaussian");
	
	// Create an other layer for color adjustment
	var colorLayer = new emage.Layer("buildin.coloradjust");
	
	// Add layers to processor and update the image
	processor.add(blurLayer);
	processor.add(colorLayer);
	processor.update();
	
	// Replace the gaussian blur with lens blur and update again
	blurLayer.use("buildin.lensblur");
	processor.update();
	
	// Set parameters of filter
	blurLayer.set("brightness", 6.0);
	blurLayer.set("blurSize", 4.0);
	
	// Or you can also write like this
	blurLayer.set({
		brightness : 6.0,
		blurSize : 4.0
	})
	
	// Export the final image
	var canvas = emage.canvas;
	var img = new Image;
	img.src = canvas.toDataURL();

Supported filters

Most of the filters is from GPUImage

---

Gaussian Blur

buildin.gaussian

• blurSize : 2.0

---

Box Blur

buildin.boxblur

• blurSize : 2.0

---

Lens Blur

buildin.lensblur

• blurSize : 0.4
• brightness : 6.0

---

Color Adjust

buildin.coloradjust

• brightness : 0.0
• gamma : 1.0
• contrast : 1.0
• exposure : 0.0
• saturation : 1.0

---

Color Matrix

buildin.colormatrix

• colorMatrix : [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]
• intensity : 1.0

---

Sepia

buildin.sepia

---

Color Lookup

buildin.lut

• lookup : Image

---

Sobel Edge Detection

buildin.sobel

---

Toon Effect

buildin.toon

---

Sketch Effect

buildin.sketch

Histogram compute

Histogram compute is done in shaders and can be quite efficient

	// Pass in the image you want to compute histogram
	var histogram = new emage.Histogram(image);
	
	// Set down sample rate
	histogram.downSample = 1/4;
	
	// Compute the histogram and get the result
	histogram.update();	
	// It will return a UnitArray(256) which store the histogram of red channel
	var redChannel = histogram.channels.red;
	// And other channels
	var blueChannel = histogram.channels.blue;
	var luminanceChannel = histogram.channels.luminance;