qweb report - embedded your image to report

Sometimes, when you need to custom your report header, add another image as logo, as usual, if you add image with path as
    <img src="/addons/module/script/src/images/a.jpg" />
It does not render as you want when printing as pdf. (image missing).
Just base64 image, and change your tag as below:
    <img src="data:image/jpg;base64, base64-encode"/>
It will render image successfully.