Magento – Import product image using dataflow profiles

As far as I concern it is not possible with neither generic Magento import, nor with Magmi. Some commercial import script might do it though.

To me the closest bet would be customizing Magmi image plugin which is quite easy.

In short: Don't use Dataflow for anything, it's deprecated. Yoav Kutner once (2011) said that Dataflow is not usable, and that was the reason they added ImportExport in Magento 1.5. The main disadvantage of Dataflow is its very low speed.

ImportExport is much faster. It's not perfect as its CSV format is not too intuitive (I have summarized it at http://www.integer-net.com/2012/04/04/importing-products-with-the-import-export-interface/), it doesn't support all product types (only simple, virtual, grouped and configurable) and the export supports even less functions (for example no grouped products). But it's very reliable and faster than all other import methods. And it still has a lot of features, like product relations, custom options, product images and tier prices. By the way, the CSV format is different from the Dataflow format, the two modules are not compatible to each other.

I have written a comparison of all import methods I know at http://www.integer-net.com/2014/05/27/product-import-with-magento/. It includes a description of all methods (among them Dataflow and ImportExport), a comparison of features and performance tests.