我正在尝试在透明的不规则形状周围添加边框
.png
图像,所以我认为最好的方法是绘制两次,将图像转换为选择的颜色,在原始图像后面绘制几个像素
var img = new Image( );
img.onload = function( ) {
var borderSize = 4;
// convert img to a solid color before drawing
img.color = 'red';
ctx.drawImage( img, -borderSize/2, -borderSize/2, 100 + borderSize, 100 + borderSize );
// reset img
img.color = 'reset';
ctx.drawImage( img, 0, 0, 100, 100 );
};
img.src = 'transparentImage.png'; //image is a transparent irregular shape ( e.g: a tree )
如何将透明图片临时转为纯色?