Image Sharpening Module added

docs/MODULES.md

@@ -41,11 +41,12 @@ List of Module Documentations
 36. [Rotate](#rotate-module)
 37. [Saturation](#saturation-module)
 38. [Segmented-Colormap](#segmented-colormap-module)
-39. [Text-Overlay](#text-overlay)
-40. [Threshold](#threshold)
-41. [Tint](#tint)
-42. [WebGL-Distort](#webgl-distort-module)
-43. [White-Balance](#white-balance-module)
+39. [Sharpen](#sharpening-module)
+40. [Text-Overlay](#text-overlay)
+41. [Threshold](#threshold)
+42. [Tint](#tint)
+43. [WebGL-Distort](#webgl-distort-module)
+44. [White-Balance](#white-balance-module)
 
 
 ## add-qr-module
@@ -667,6 +668,20 @@ where `options` is an object with the property `colormap`. `options.colormap` ca
 * A custom array.
 
 
+## sharpen-module
+
+This module is used to sharpen the pixels of the image using a 3x3 convolution filter.
+#### Usage
+
+```js
+  sequencer.loadImage('PATH')
+           .addSteps('sharpen',options)
+           .run()
+```
+
+where `options` is an object with the property `sharpenStrength`, which can be set to achieve the desired level of sharpening on the image.
+
+
 ## Text Overlay
 
 The modules allows to add text to image in both browser and node environment. We have the options to modify the font-size and also support few font-styles. The text color can also be modified.

src/Modules.js

@@ -46,6 +46,7 @@ module.exports = {
   'rotate': require('./modules/Rotate'),
   'saturation': require('./modules/Saturation'),
   'shadow': require('./modules/Shadow'),
+  'sharpen': require('./modules/Sharpen'),
   'text-overlay': require('./modules/TextOverlay'),
   'threshold': require('./modules/Threshold'),
   'tint': require('./modules/Tint'),

src/modules/Sharpen/Module.js

@@ -0,0 +1,46 @@
+/*
+  Sharpen an image
+*/
+module.exports = function Sharpen(options, UI) {
+
+  let defaults = require('./../../util/getDefaults.js')(require('./info.json'));
+  options.sharpenStrength = options.sharpenStrength || defaults.sharpenStrength;
+  options.sharpenStrength = parseFloat(options.sharpenStrength); //returns a float
+  let output;
+
+  function draw(input, callback, progressObj) {
+
+    progressObj.stop(true);
+    progressObj.overrideFlag = true;
+
+    let step = this;
+
+    function extraManipulation(pixels) {
+      pixels = require('./Sharpen')(pixels, options.sharpenStrength);
+      return (pixels);
+    }
+
+    function output(image, datauri, mimetype, wasmSuccess) {
+      step.output = { src: datauri, format: mimetype, wasmSuccess, useWasm: options.useWasm };
+    }
+
+    return require('../_nomodule/PixelManipulation.js')(input, {
+      output: output,
+      ui: options.step.ui,
+      inBrowser: options.inBrowser,
+      extraManipulation: extraManipulation,
+      format: input.format,
+      image: options.image,
+      callback: callback,
+      useWasm:options.useWasm
+    });
+
+  }
+  return {
+    options: options,
+    draw: draw,
+    output: output,
+    UI: UI
+  };
+};
+

src/modules/Sharpen/Sharpen.js

@@ -0,0 +1,48 @@
+// Generates a 3x3 convolution sharpening kernel
+function kernelGenerator(strength = 1) { //default value of sharpeningStrength set to 1
+
+  let kernel = [
+    [0, -1 * strength, 0],
+    [-1 * strength, 5 * strength, -1 * strength],
+    [0, -1 * strength, 0]
+  ];
+  return kernel;
+}
+
+module.exports = exports = function(pixels, sharpen) {
+  const pixelSetter = require('../../util/pixelSetter.js');
+
+  let kernel = kernelGenerator(sharpen), // Generate the kernel based on the strength input.
+    pixs = { // Separates the rgb channel pixels to convolve on the GPU.
+      r: [],
+      g: [],
+      b: [],
+    };
+  for (let y = 0; y < pixels.shape[1]; y++){
+    pixs.r.push([]);
+    pixs.g.push([]);
+    pixs.b.push([]);
+
+    for (let x = 0; x < pixels.shape[0]; x++){
+      pixs.r[y].push(pixels.get(x, y, 0));
+      pixs.g[y].push(pixels.get(x, y, 1));
+      pixs.b[y].push(pixels.get(x, y, 2));
+    }
+  }
+
+  const convolve = require('../_nomodule/gpuUtils').convolve; // GPU convolution function.
+
+  const conPix = convolve([pixs.r, pixs.g, pixs.b], kernel); // Convolves the pixels (all channels separately) on the GPU.
+
+  for (let y = 0; y < pixels.shape[1]; y++){
+    for (let x = 0; x < pixels.shape[0]; x++){
+      var pixelvalue = [Math.max(0, Math.min(conPix[0][y][x], 255)),
+        Math.max(0, Math.min(conPix[1][y][x], 255)),
+        Math.max(0, Math.min(conPix[2][y][x], 255))];
+
+      pixelSetter(x, y, pixelvalue, pixels); // Sets the image pixels according to the sharpened values.
+
+    }
+  }
+  return (pixels);
+};

src/modules/Sharpen/index.js

@@ -0,0 +1,4 @@
+module.exports = [
+  require('./Module'),
+  require('./info.json')
+];

src/modules/Sharpen/info.json

@@ -0,0 +1,15 @@
+{
+    "name": "sharpen",
+    "description": "Applies a sharpening filter given by the intensity value",
+    "inputs": {
+        "sharpenStrength": {
+            "type": "float",
+            "desc": "Amount of sharpening (More sharpening gives more detail, but may lead to overexposure)",
+            "default": 1,
+            "min": 1,
+            "max": 1.5,
+            "step": 0.05
+        }
+    },
+    "docs-link":"https://github.com/publiclab/image-sequencer/blob/main/docs/MODULES.md#sharpen-module"
+}