Refer to the Documentation page for each specific request and the supported Parameters
Zooming in and out on the image is simply rendering the same size image (ImageWidth and ImageHeight), but modifying the Box.* parameters to change the bounding box in which the design is rendered.
In all samples below, we are zooming in/out on the center of the image. For example, the pixel at (250, 250) of a 500x500 pixel image. Zooming in is making the bounding box bigger. Zooming out is making the bounding box smaller. Panning around the design is moving the bounding box up/down & left/right.
/api/Lettering/Render?Text=Pulse&ImageWidth=500&ImageHeight=500&Background=ffeeeeee
/api/Lettering/Render?Text=Pulse&ImageWidth=500&ImageHeight=500&Background=ffeeeeee&Box.Left=125&Box.Top=125&Box.Right=375&Box.Bottom=375
/api/Lettering/Render?Text=Pulse&ImageWidth=500&ImageHeight=500&Background=ffeeeeee&Box.Left=-250&Box.Top=-250&Box.Right=750&Box.Bottom=750
/api/Lettering/Render?Text=Pulse&ImageWidth=500&ImageHeight=500&Background=ffeeeeee&Box.Left=-750&Box.Top=-750&Box.Right=1250&Box.Bottom=1250
/api/Lettering/Render?Text=Pulse&ImageWidth=500&ImageHeight=500&Background=ffeeeeee&Box.Left=-1250&Box.Top=-750&Box.Right=750&Box.Bottom=1250