To specify a DPI via XML API, please use the following format. To see the full documentation on Image2Image controls, please view our master API documenation here.
<?xml version="1.0"?>
<query>
<format>
<output>image</output>
<size>100x0</size>
<image_format>png</image_format>
<resize_method>resize</resize_method>
<dpi>72</dpi>
<destination/>
</format>
</query>
