码农干货系列【4】图像识别之矩形区域搜索


var increasePixel &＃61; 1, leftIncreasePixel &＃61; 2, rightIncreasePixel &＃61; 2, upIncreasePixel &＃61; 2, downIncreasePixel &＃61; 2;
function searchTransparentRectByTargetPoint(p) {

var p1 &＃61; { x: p.x - leftIncreasePixel, y: p.y - upIncreasePixel };
var p2 &＃61; { x: p.x rightIncreasePixel, y: p.y - upIncreasePixel };
var p3 &＃61; { x: p.x rightIncreasePixel, y: p.y downIncreasePixel };
var p4 &＃61; { x: p.x - leftIncreasePixel, y: p.y downIncreasePixel };

var breakTag &＃61; true;
if (!isXLineTransparent(p1, p2)) {
upIncreasePixel &＃61; increasePixel;
breakTag &＃61; false;
}
if (!isYLineTransparent(p2, p3)) {
breakTag &＃61; false;
rightIncreasePixel &＃61; increasePixel;
}
if (!isXLineTransparent(p4, p3)) {
breakTag &＃61; false;
downIncreasePixel &＃61; increasePixel;
}
if (!isYLineTransparent(p1, p4)) {
breakTag &＃61; false;
leftIncreasePixel &＃61; increasePixel;
}

if (breakTag) {
return [p1.x, p1.y, p3.x - p1.x, p3.y - p1.y];
} else {
return searchTransparentRectByCenterPoint(p);
}
}


function isXLineTransparent(p1, p2) {
var _y &＃61; p2.y;
for (var i &＃61; p1.x; i var startIndex &＃61; this.getImageDataStartIndexByPosition({ x: i, y: _y });
var totalPixel &＃61; this.imageData.data[startIndex] this.imageData.data[startIndex 1] this.imageData.data[startIndex 2] this.imageData.data[startIndex 3];
if (totalPixel !&＃61;&＃61; 0) {
return false;
}
}
return true;
}

function isYLineTransparent(p1, p2) {
var _x &＃61; p2.x;
for (var i &＃61; p1.y; i var startIndex &＃61; this.getImageDataStartIndexByPosition({ x: _x, y: i });
var totalPixel &＃61; this.imageData.data[startIndex] this.imageData.data[startIndex 1] this.imageData.data[startIndex 2] this.imageData.data[startIndex 3];
if (totalPixel !&＃61;&＃61; 0) {
return false;
}
}
return true;
}