天空вℓσи∂ @skyblond@qoto.org

@freemo Yeah, I wrote a lot when I was in school, and carbon black ink is better than the black dye ink.Thee dye-based one looks like dark purple instead of true black.

But now I mainly write things with pencil (easy to change the design), so the carbon ink often dried in the pen.

@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.

@trinsec @olives I saw the error page sometimes, but most of the time it is just stuck there, didn't timeout, but also not receiving data. But now it looks like fine.

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).

@henghenghengAAAAA 本来想选骑车让你锻炼身体，后来看到风俗店，四舍五入也算是锻炼身体了（

@Fermiko 因为都来长毛象啦（

@wihou @trinsec Manjaro is great, solving a lot of issues (mostly driver issues) during installation. That's a pleasant experience from my memory, despite it takes forever to install packages from aur due to connectivity issues in China.

@wihou @trinsec I do have proxy setup for my linux server at home (the fixed not moving machine). The proxy only works with tcp, but some game requires udp to work. And my setup is almost hard-coded (using iptables or nftables) and for a moving device switching between different networks? I can already dream the nightmare 😂

(Vpn is not working in China since 2012, now we have custom software to cover the proxy)

@trinsec I do tried arch 5 or 6 years ago, following the guide, installing my system line by line, then ran into a circle where I need internet to download driver, but I need driver to access the internet, and all I had is a laptop using weird network chip. LOL

Since then I never touched vanilla arch again and tried manjaro several times. Now I have settled with opensuse. I think for normal desktop usage, the distro isn't that different, until you have to open the terminal and do something.