You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
104 lines
2.5 KiB
104 lines
2.5 KiB
var fs = require('fs')
|
|
var path = require('path')
|
|
var Canvas = require('..')
|
|
|
|
var Image = Canvas.Image
|
|
var canvas = new Canvas(400, 267)
|
|
var ctx = canvas.getContext('2d')
|
|
|
|
var img = new Image()
|
|
|
|
img.onload = function () {
|
|
ctx.drawImage(img, 0, 0)
|
|
}
|
|
|
|
img.src = path.join(__dirname, 'images', 'squid.png')
|
|
|
|
var sigma = 10 // radius
|
|
var kernel, kernelSize, kernelSum
|
|
|
|
function buildKernel () {
|
|
var i, j, g
|
|
var ss = sigma * sigma
|
|
var factor = 2 * Math.PI * ss
|
|
|
|
kernel = [[]]
|
|
|
|
i = 0
|
|
do {
|
|
g = Math.exp(-(i * i) / (2 * ss)) / factor
|
|
if (g < 1e-3) break
|
|
kernel[0].push(g)
|
|
++i
|
|
} while (i < 7)
|
|
|
|
kernelSize = i
|
|
for (j = 1; j < kernelSize; ++j) {
|
|
kernel.push([])
|
|
for (i = 0; i < kernelSize; ++i) {
|
|
g = Math.exp(-(i * i + j * j) / (2 * ss)) / factor
|
|
kernel[j].push(g)
|
|
}
|
|
}
|
|
|
|
kernelSum = 0
|
|
for (j = 1 - kernelSize; j < kernelSize; ++j) {
|
|
for (i = 1 - kernelSize; i < kernelSize; ++i) {
|
|
kernelSum += kernel[Math.abs(j)][Math.abs(i)]
|
|
}
|
|
}
|
|
}
|
|
|
|
function blurTest () {
|
|
var x, y, i, j
|
|
var r, g, b, a
|
|
|
|
console.log('... running')
|
|
|
|
var imgData = ctx.getImageData(0, 0, canvas.width, canvas.height)
|
|
var data = imgData.data
|
|
var width = imgData.width
|
|
var height = imgData.height
|
|
|
|
var startTime = (new Date()).getTime()
|
|
|
|
for (y = 0; y < height; ++y) {
|
|
for (x = 0; x < width; ++x) {
|
|
r = 0
|
|
g = 0
|
|
b = 0
|
|
a = 0
|
|
|
|
for (j = 1 - kernelSize; j < kernelSize; ++j) {
|
|
if (y + j < 0 || y + j >= height) continue
|
|
|
|
for (i = 1 - kernelSize; i < kernelSize; ++i) {
|
|
if (x + i < 0 || x + i >= width) continue
|
|
|
|
r += data[4 * ((y + j) * width + (x + i)) + 0] * kernel[Math.abs(j)][Math.abs(i)]
|
|
g += data[4 * ((y + j) * width + (x + i)) + 1] * kernel[Math.abs(j)][Math.abs(i)]
|
|
b += data[4 * ((y + j) * width + (x + i)) + 2] * kernel[Math.abs(j)][Math.abs(i)]
|
|
a += data[4 * ((y + j) * width + (x + i)) + 3] * kernel[Math.abs(j)][Math.abs(i)]
|
|
}
|
|
}
|
|
|
|
data[4 * (y * width + x) + 0] = r / kernelSum
|
|
data[4 * (y * width + x) + 1] = g / kernelSum
|
|
data[4 * (y * width + x) + 2] = b / kernelSum
|
|
data[4 * (y * width + x) + 3] = a / kernelSum
|
|
}
|
|
}
|
|
|
|
var finishTime = Date.now() - startTime
|
|
for (i = 0; i < data.length; i++) {
|
|
imgData.data[i] = data[i]
|
|
}
|
|
|
|
ctx.putImageData(imgData, 0, 0)
|
|
console.log('... finished in %dms', finishTime)
|
|
}
|
|
|
|
buildKernel()
|
|
blurTest()
|
|
|
|
canvas.createPNGStream().pipe(fs.createWriteStream(path.join(__dirname, 'kraken.png')))
|
|
|