In rml report you can use this:

<image x="1.0cm" y="24.0cm" width="5.0cm">[[ company.logo or removeParentNode('image') ]]</image>

Im mako/qweb reports

<img src="data:image/png;base64,${line.product_id.image}" />
<img src="data:image/jpeg;base64,${company.logo}" />

(or)
On your mako template:

${helper.embed_image('png', object.image,50,50) | n}

Where

helper.embed_image(image_type, object_image,width,height)