[Redmi Note 7] Camera - AI & 48 MP Weird Results...


Feb 1, 2013
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#1
Hey there,

I've just bought a Xiaomi Redmi Note 7 (Hongmi Note 7 or 小米红米Note 7) and started doing some camera tests to see which settings are the best. I'm opening this thread to share some observations that I did concerning the so-called "AI" mode and the "48 megapixels" mode, or I should say, observations that I didn't do .

I think a picture will illustrate it much better than a long paragraph so you will judge by yourself.


At first here is the "normal mode" and the "AI mode":

1_3_Normal-AI.jpg

(Normal mode is inside the squares while the rest is "AI" mode)​

Honestly even viewed at 200% on Photoshop, I see no difference at all (light, shadows, contrast, quality, digital noise, color aberration, ...). Well, this didn't surprise me that much, I'm still not really convinced by these AI functions. But the next one let me more doubtful about Xiaomi....


1_6_Normal-48MP_1.jpg


1_6_Normal-48MP_2.jpg

Of course none of these pictures were edited to improve or decrease the image quality, colors, exposure, ... I just opened the 48 megapixels picture (8000x6000) in Photoshop and then imported and resized the picture taken in normal mode (4000x3000) to put them side by side.

I know that by doing so the normal picture is resized by 400% and so will loose image quality (resizing doesn't add pixels), but as you can see even once resized by 400% the normal picture doesn't look that much different from the 48 MP one (in terms in image finesse and resolution). Some branches of the trees are slightly more fine, but if you look at the poster or the stair rail the normal mode looks better.

As I already said, you will be the judge, but it looks to me that, even if 48 MP mode does take 8000x6000 pictures, the image quality is pretty much the same. Maybe it's limited by the camera sensor or maybe 48 MP is just a fake mode that upscale 4000x3000 normal pictures to 8000x6000... What's sure is that one file is 6.7 Mo while the other is 17.5 Mo, not sure that it is worth the quality "increase".


MIUI version used: 10.2.8.0 by Xiaomi.eu (Android version: 9.0) with original camera app. But I actually tried several other apps (Google official one, Open Camera, ...), none of them allows me to take picture of a resolution higher than 4000x3000. Same info in Aida64.




Cheers!



Sakat





#Edit: After more research the camera of the Redmi Note 7 is a S5KGM1, which is a "48Mp 4in1 to 12Mp (1.6um)":
https://www.samsung.com/semiconductor/image-sensor/mobile-image-sensor/S5KGM1/
For what I understood they use a kinda of way to get better image quality by having 4 pixels mixed into one but the processed image isn't really 48 Mp. Maybe the normal mode takes advantages of it but the "48 MP" option in Pro Mode is still not really worth it based on the pictures I took and it still doesn't really explain what's the process to output a 8000x6000 resolution picture (which the CPU of the Redmi Note 7 apparently can't support). More info in Spanish here:
https://elandroidelibre.elespanol.com/2019/01/como-funciona-camara-redmi-note-7-48-mpx.html
 
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