CONSEGUI!!!!
Segue resposta para quem desejar um dia fazer:
no html, coloquei:
<img id="img_logoEmpresa" src="./logo.bmp" />
no js, coloquei:
$(document).ready(function(){
$("#img_logoEmpresa").hide();
$("#btnTeste").click(function(){
.
.
.
var img = document.getElementById("img_logoEmpresa");
imgEncode = getBase64Image(img);
var docDefinition = {
content: [
{
style: 'tableCabecalho',
table:{
widths: [100, '*', 100],
heigths: 50,
body: [
[{
margin:[0,10],
image: 'data:image/jpeg;base64,'+imgEncode,
width: 100,
rowSpan: 2
},
.
.
.
.
}
}
}
}
}
function getBase64Image(img) {
// Create an empty canvas element
var canvas = document.createElement("canvas");
canvas.width = img.width;
canvas.height = img.height;
// Copy the image contents to the canvas
var ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0);
// Get the data-URL formatted image
// Firefox supports PNG and JPEG. You could check img.src to
// guess the original format, but be aware the using "image/jpg"
// will re-encode the image.
var dataURL = canvas.toDataURL("image/png");
return dataURL.replace(/^data:image\/(png|jpg);base64,/, "");
}