天空вℓσи∂ @skyblond@qoto.org

You have to subscribe to YouTube premium to use the screen lock feature? (The feature to prevent false touch when watching videos).

If you have to subscribe to the premium plan to get high bitrate videos, that's acceptable. But screen lock? VLC has this feature for years, and it's free of charge.

Google, really? 🤔

Talking about ink, I just bought some ink cartridges from Platinum. I know I don't like this thing, but I think keep carbon ink dried in pen is much worse.

@freemo I have a #3776 Century (F tip) from Platinum, it's the cheapest model (~100 USD). I started using it since high school and now I still use it.

I'm not a fan of collecting pens, but I do like using pens since I don't need to swap the cartridges (the Gel Pen Refills). This pen works very well. Before that, I was using LAMY (also the cheapest model, about ~20 USD), but it had a lot of problems and I eventually decided to invest more.

I like using carbon black ink, however it's not good for pens, especially when you don't write a lot. But this pen handles it pretty well.

But now I rarely do handwriting after graduated. I don't know if this is good, but the ultrasonic cleaner is pretty good at dealing with dried carbon ink.

Did goto just go offline for a while?

To resist jpeg compression, I use the LL matrix of the Haar DWT result (which should contain low freq data that can be preserved by JPEG), then chunk it into 4x4 chunks, then apply DCT and SVD to each chunk, then encode the bits into the first and second element of the S matrix.

It certainly works, but any other steganography could work too if it leaves a strong and visible mark on the image, which surely can be preserved by JPEG compression (Modify low freq in FFT space, or just use the MSB).

I swear there are visible stripes in the dark area, like the screenshot I take in picture 4. But I don't know why it's not visible anymore, probably because of the compression. LOL

Tried to implement a paper based on its abstract, because I'm not willing to pay 40 USD. The result is a mix of success and failure.

The paper introduced a steganography called DWT-DCT-SVD, which is applying DWT to a picture and then applying DCT and finally encoding bits into the S matrix of the SVD operation.

The first picture is encoded picture after jpeg compression (photoshop, quality 8, raw picture is 90MB in png), picture 2 is the intended decoded result, and picture 3 is the jpeg decoded result. I would say not bad...

... unless you zoom in on the picture and notice there are a lot of stripes giving off the fact that this picture is suspicious (picture 4).

Even after 5 years, Detroit: Become human is still a great game to enjoy.

And let chatgpt playing it just take the game to a higher level.

Also, I feel like it's a very old game (decades ago), but actually just 5 years ago. hmmmm

For the question in the begining of the video, the first idea I came up is the flow of energy. Something like water, which you can generate electricity from it if it's high engough. You have to get rid of the water, but you extract the potential from it. The energy might be same, you have to get rid of the energy, but you extract something from it to use.

Later in the video, I learn that kind of things are called entropy.

Phsysic is fun, as long as there is no exam.
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The Most Misunderstood Concept in Physics
by Veritasium
https://www.youtube.com/watch?v=DxL2HoqLbyA