An image processing pipeline may process image data at multiple rates. A stream of raw pixel data collected from an image sensor for an image frame may be processed through one or more pipeline stages of an image signal processor. The stream of raw pixel data may then be converted into a full-color domain and scaled to a data size that is less than an initial data size for the image frame. The converted pixel data may be processed through one or more other pipelines stages and output for storage, further processing, or display. In some embodiments, a back-end interface may be implemented as part of the image signal processor via which image data collected from sources other than the image sensor may be received and processed through various pipeline stages at the image signal processor.