I am investigating a resize example with Vitis flow. It does not use DMA. Since OpenCL handles data transaction in this approach, I still have no idea how data stream is fetch into and get from resize kernel.
DMA is used to stream data to/from the IP, not to control the IP.
The control is done through the AXI slave port.
You can modify the HLS code to read directly from PS DRAM (where the image data is stored). This would involved switching the AXI stream interfaces to AXI masters.
You could also modify the code or create your own design with the the data width converter removed and functionality built in to your IP.