How to download an image from svcene7 programmatically

I had a requirement to create a zip file downloading a set of images from AEM and i used an existing rendition of an image for the same and that works and I am able to download a rendition of an image and create a zip file. I used Asset API for the same.

final Asset asset = DamUtil.resolveToAsset(assetResource);
InputStream in = asset.getRendition(DAM_THUMBNAIL).getStream(); 

Now there is a requirement to create a custom rendition for an image using imageprofile in AEM, that will create a rendition in scene7 server and not in AEM. i Have to include those scene7 rendition images in my zip.

Does anyone have any samples on how to call the scene7 API to download a image rendition as inputstream?