The evaluation of the image processor must be divided into two distinct aspects, as the Haier M90E behaves inconsistently here. The first issue is the upscaling itself, which is the process of scaling lower resolution content to 4K. In this task, the television performs quite decently. The algorithms effectively enhance detail, making the final image relatively sharp, clear, and readable. In this respect, it’s hard to have major complaints about the device.
The situation is completely different with materials that have a high degree of compression, which we encounter in older recordings or on platforms like YouTube with a lower bitrate. Here, the processor struggles with smoothing tonal transitions and masking the imperfections of the source. The television fails to hide compression blocks, resulting in a very harsh, "digital" character of the image. The lack of effective artifact reduction can certainly deter viewers from watching lower quality content on this screen.
For scaling and digital processing in the Dreame S100, the technology used is proudly called Dreamind™ Pro AI by the manufacturer. However, it must be clearly stated that this is not a proprietary processor but rather a marketing term for a chip from MediaTek – specifically, the model MT5889. Unfortunately, we are talking about a rather outdated unit from a time when MediaTek lagged significantly behind the competition in terms of performance. This, unfortunately, has a direct impact on the image, as this chip also handles that. The upscaling in the S100 is fairly average, and the processor has a tendency to artificially over-sharpen edges (fortunately, this can be somewhat tempered with the sharpness slider in the menu). In the options, we also find a feature called "Contour Smoothing," which theoretically is supposed to improve tonal transitions. In practice, it contributes almost no improvement – setting it to any level rarely eliminates visible colour banding, but it can unnecessarily blur elements of the image that should remain sharp.
Another issue is the phenomenon of overscan (cropping the edges of the frame), which is practically visible all the time. Although there is the possibility to set the screen to display the full frame in low-resolution materials, it requires activating the aforementioned Filmmaker mode. And as you may know, this mode completely blocks any changes to other sliders in the picture menu. In our test tables, we noted that the television offers an option to disable overscan, as such a function technically exists in the system – however, in everyday use, while maintaining reasonable picture settings, you will not be able to take advantage of it.