On Microsoft's system, Sleeping Dogs adopts a native 1200x720 presentation, with an 80-pixel horizontal upscale to 720p, while on the PS3 we're looking at a much lower 1152x640, which has more severe implications with regards to overall image quality. Anti-aliasing on both consoles is a post-process, most likely provided by NVIDIA's popular FXAA solution, although we find that the PS3 uses a more aggressive edge-detect algorithm in order to smooth over the additional jaggies created by the heavy upscale.
While the 360 game gives a passable impression of a native 720p presentation, it looks significantly blurrier on the PS3: the combination of the much heavier upscaling and a stronger FXAA solution covering the final image in a veil of softness. Finer texture details that are visible on both platforms are smoothed over and edges feature a distinct softness that is regularly apparent with anti-aliased sub-HD games. Specular highlights are also subdued on the PS3 due to the stronger edge-detection being employed, although this doesn't come across as a particular downside given that the characters can look a little too shiny in some scenes on the 360.
Aside from the obvious resolution differences, it is clear that the PS3 version is missing some of the more intricate texture details found on the 360, a situation not helped by the more aggressive FXAA implementation. Additionally, we also find that normal maps feature less distinctive bumps and ripples, leading to the affected surfaces looking a touch blockier in nature. The reason for this is that lower resolution artwork is used on many objects throughout the game, thus resulting in visible detail loss, while normal maps appear to be using a different, more lossy compression scheme which creates artifacts on surfaces which use the effect - the Xenos GPU has access to improved texture compression technology compared to RSX, which may explain this.