var canvas = document.getElementById("canV");
var ctx = canvas.getContext("2d");
// Groover API log dependency replacement
function log(data){
// console.log(data); // just suck it up
}
// Groover Bitmaps API dependency replacement
// Extracted from Groover.Bitmaps
var createImage= function(w,h){ // create a image of requier size
var image = document.createElement("canvas");
image.width = w;
image.height =h;
image.ctx = image.getContext("2d"); // tack the context onto the image
return image;
}
function embose(imageDataSource,imageDataDestination, method, emboseImageEdge, perceptualCorrect,edgeOnly){
"use strict";
var dataS = imageDataSource.data;
var dataD = imageDataDestination.data;
var w = imageDataSource.width;
var h = imageDataSource.height;
if(dataS.length !== dataD.length){
return false; // failed due to size mismatch
}
var embos,size,halfSize;
var lMethod = method.toLowerCase(); // some JS engines flag reasignment of
// arguments as unoptimised as this
// is computationally intensive create a
// new var for lowercase
if(lMethod === "2 pixel soft"){
embos = [
-0.25 , -0.5 , -1, -1 , 0.5,
-0.5 , -1 , -1, 1 , 1,
-1 , -1 , 1, 1 , 1,
-1 , -1 , 1, 1 , 0.5,
-0.5 , 1, 1, 0.5 , 0.25
];
size = 5;
halfSize = 2;
}else
if(lMethod === "2 pixel"){
embos = [
-1 , -1 , -1, -1 , 1,
-1 , -1 , -1, 1 , 1,
-1 , -1 , 1, 1 , 1,
-1 , -1 , 1, 1 , 1,
-1 , 1, 1, 1 , 1
];
size = 5;
halfSize = 2;
}else
if(lMethod === "1 pixel"){
embos = [
-1 , -1, -1,
-1, 1, 1,
1 , 1, 1
];
size = 3;
halfSize = 1;
}
var deb = 0
var x,y,l,pl,g,b,a,ind,scx,scy,cx,cy,cInd,nearEdge,pc;
pc = perceptualCorrect; // just for readability
for(y = 0; y < h; y++){
for(x = 0; x < w; x++){
ind = y*4*w+x*4;
l = 0;
nearEdge = false;
if(dataS[ind+3] !== 0){ // ignor transparent pixels
for (cy=0; cy<size; cy++) {
for (cx=0; cx<size; cx++) {
scy = y + cy - halfSize;
scx = x + cx - halfSize;
if (scy >= 0 && scy < h && scx >= 0 && scx < w) {
cInd = (scy*w+scx)*4;
if(dataS[cInd+3] === 0){
nearEdge = true;
}
l += pc?(embos[cy*size+cx] *
((Math.pow(dataS[cInd++]*0.2126,2)+
Math.pow(dataS[cInd++]*0.7152,2)+
Math.pow(dataS[cInd++]*0.0722,2)
)/3)):
(embos[cy*size+cx] *
((dataS[cInd++]+
dataS[cInd++]+
dataS[cInd++]
)/3));
}else
if(emboseImageEdge){
nearEdge = true;
}
}
}
if((nearEdge && edgeOnly) || ! edgeOnly){
if(pc){
pl = Math.sqrt((Math.pow(dataS[ind]*0.2126,2) + Math.pow(dataS[ind+1]*0.7152,2) + Math.pow(dataS[ind+2]*0.0722,2))/3);
l = Math.sqrt(Math.max(0,l));
if(pl > 0){
pl = l/pl;
dataD[ind] = Math.sqrt(dataS[ind]*dataS[ind++]*pl);
dataD[ind] = Math.sqrt(dataS[ind]*dataS[ind++]*pl);
dataD[ind] = Math.sqrt(dataS[ind]*dataS[ind++]*pl);
dataD[ind] = dataS[ind]; // alpha not effected
}else{ // black pixel
dataD[ind++] = 0;
dataD[ind++] = 0;
dataD[ind++] = 0;
dataD[ind] = dataS[ind];
}
}else{
l = Math.max(0,l);
pl = (dataS[ind]+dataS[ind+1]+dataS[ind+2])/3;
if(pl > 0){
pl = l/pl;
dataD[ind] = dataS[ind++]*pl;
dataD[ind] = dataS[ind++]*pl;
dataD[ind] = dataS[ind++]*pl;
dataD[ind] = dataS[ind]; // alpha not effected
}else{ // black pixel
dataD[ind++] = 0;
dataD[ind++] = 0;
dataD[ind++] = 0;
dataD[ind] = dataS[ind];
}
}
}else{ // if not edge then just copy image pixel to dest
dataD[ind] = dataS[ind++];
dataD[ind] = dataS[ind++];
dataD[ind] = dataS[ind++];
dataD[ind] = dataS[ind];
}
}else{ // set transparent pixel to zero
dataD[ind+3] = 0;
}
}
}
// all done
return true; // return success
}
var img = createImage(128,128);
img.ctx.font = "32px arial black";
img.ctx.textAlign = "center";
img.ctx.textBaseline = "middle";
img.ctx.lineCap = "round";
img.ctx.lineJoin = "round";
img.ctx.lineWidth = 4
img.ctx.strokeStyle = "#3AD";
img.ctx.fillStyle = "#334";
img.ctx.strokeText("LOGO!",64,64);
img.ctx.fillText("LOGO!",64,64);
ctx.drawImage(img,0,0);
var img1 = createImage(128,128);
var imgData = img.ctx.getImageData(0,0,128,128);
var imgData1 = img1.ctx.getImageData(0,0,128,128);
if(embose(imgData,imgData1,"2 pixel soft",false, true, false)){
img1.ctx.putImageData(imgData1,0,0);
log("ONe")
ctx.drawImage(img1,128,0);
}
img.ctx.fillStyle = "#DA3"; // make is look better for the sell ;)
img.ctx.fillText("LOGO!",64,64);
var imgData = img.ctx.getImageData(0,0,128,128);
var img1 = createImage(128,128);
var imgData1 = img1.ctx.getImageData(0,0,128,128);
if(embose(imgData,imgData1,"2 pixel",false, true, true)){
img1.ctx.putImageData(imgData1,0,0);
ctx.drawImage(img1,0,128);
}
var img1 = createImage(128,128);
var imgData1 = img1.ctx.getImageData(0,0,128,128);
if(embose(imgData,imgData1,"1 pixel",false, false, false)){
img1.ctx.putImageData(imgData1,0,0);
ctx.drawImage(img1,128,128);
}
.canC {
width:256px;
height:256px;
}
<canvas class="canC" id="canV" width=256 height=256></canvas>
您可以找到使用 “行进广场” 算法外边缘。此前的SO帖子显示了它的使用示例:http://stackoverflow.com/questions/25873601/how-can-i-get-all-coordinates-of-shapes-edge-in-canvas/25875512#25875512 – markE
啊!发现它:http://stackoverflow.com/questions/25467349/in-a-2d-canvas-is-there-a-way-to-give-a-sprite-an-outline – Kaiido
由于这是一次性操作1)处理时间无关紧要,你甚至可以采取“巨大”的时间,比如...... 50ms来处理一次图像。但是2)如何在图像处理软件中进行一次更改? Rq还指出一些公司希望保持对视觉效果的控制,并且更愿意为您提供一个徽标*,以便他们更改以符合特定的显示要求。 – GameAlchemist