TCL C75B has a tone transition smoothing function, but unfortunately, we cannot commend it. Regardless of the selected level – low or high – tone transitions in older materials remained visible, as if the function wasn't working at all. It's hard to say anything positive about it, as in practice it seems completely useless.
The image scaling is better. The television performs quite decently, although on thinner elements, like branches in the background, you can notice slight jaggedness. However, this is not something that significantly interferes with daily viewing.
Unfortunately, a bigger problem turned out to be overscan, which is cutting off the edges of the image. In our tests, there were instances where news tickers or other elements near the edge of the screen were cut off. This is definitely something to pay attention to, especially if we use the television for watching news programmes or content with text on the screen.
For scaling and digital processing in the Dreame S100, the technology that the manufacturer proudly calls Dreamind™ Pro AI is responsible. However, it must be clearly stated that this is not a proprietary processor, but merely a marketing name for a chip made by MediaTek – more precisely, the MT5889 model. Unfortunately, we are talking about a rather outdated unit, from a time when MediaTek lagged significantly behind the competition in terms of performance.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 that is what this chip also deals with. The upscaling in the S100 is quite mediocre, and the processor has a tendency to heavily and artificially sharpen edges (fortunately, this can be somewhat tempered with the sharpness slider in the menu). In the options, we also find the "Contour Smoothing" feature, which theoretically is supposed to improve tonal transitions. In practice, it offers almost no improvement – setting it to any level rarely eliminates visible banding of colours, but it can unnecessarily blur elements of the image that should remain sharp.
A separate issue is the phenomenon of overscan (cropping the edges of the frame), which is noticeable here practically all the time. Although there is an option to set the screen to display the full frame in low-resolution materials, this requires activating the previously mentioned Filmmaker mode. And as you know, this mode completely blocks the adjustment of any other sliders in the picture menu. In our test tables, we marked that the television offers an option to disable overscan, as technically such a function exists in the system – however, in everyday use, when maintaining sensible image settings, you will not be able to take advantage of it.