Topic: Wtf is pixel data?

Anonymous A started this discussion 1 hour ago #138,069

It’s in the name.

Anonymous A (OP) double-posted this 1 hour ago, 3 minutes later[^] [v] #1,461,183

Every pixel has 3 subpixels for the 3 primary colors of light: red, green, and blue. The brightness of each subpixel is represented as 8 1’s and 0’s of binary.

Anonymous A (OP) triple-posted this 1 hour ago, 2 minutes later, 6 minutes after the original post[^] [v] #1,461,184

png images uses lossless compression. PNG uses the DEFLATE algorithm, which basically uses pointers to link back to sequences of bits that were already previously used in the image, making it better for screenshots and images with solid colors.

JPEG uses lossy compression based on discrete cosine transform which basically turns the image into a sum of cosines, and then the smaller details are omitted, resulting in an image that looks mostly the same but uses vastly less binary data.

Anonymous B joined in and replied with this 1 hour ago, 23 minutes later, 30 minutes after the original post[^] [v] #1,461,187

Huh an actually interesting thread on minichan. Really weird day today.

Mr. Bloody Lemonade !0JqexkOGBc joined in and replied with this 1 hour ago, 8 minutes later, 38 minutes after the original post[^] [v] #1,461,190

@previous (B)
Another interesting related topic is linear and non linear color spaces. Back when they still used CRT monitors, there’s an interesting coincidence that human brightness perception doesn’t increase linearly as the number of photons increases and CRT monitors also don’t increase in brightness linearly with an increase in voltage. They both coincidently increase with approximately the square root. So that was built into the sRGB color standard. But there are a couple problems with it: it uses 8 bits because the 8 bit byte standard comes from ASCII being designed to handle the Latin character range, but 256 values of intensity actually isn’t enough to cover the full range of colors that humans can see, so more values are used for brighter intensities than darker intensities. This can cause color banding artifacts when images are increased in brightness digitally. And since sRGB is non Linear A naive implementation of brightening an image will lose data, so you have to linearize it, multiply it, then convert it back into sRGB.

Mr. Bloody Lemonade !0JqexkOGBc double-posted this 1 hour ago, 2 minutes later, 40 minutes after the original post[^] [v] #1,461,191

The difficulty of quantifying all colors humans can see into numbers actually predates digital displays. Attempts to create color spaces that can capture all colors humans can see actually dates back to the 1930s. For example CIE XYZ was an attempt to create a color space that could represent more colors than humans can see, and was linear. Although the sacrifice they made was using 3 primary colors that do not actually exist called X, Y, and Z.

https://en.wikipedia.org/wiki/CIE_1931_color_space

Mr. Bloody Lemonade !0JqexkOGBc triple-posted this 55 minutes ago, 8 minutes later, 49 minutes after the original post[^] [v] #1,461,196

I don’t remember exactly what it is, but they don’t use 1/2 it’s 1/2.2 or 1/2.4.

Mr. Bloody Lemonade joined in and replied with this 50 minutes ago, 4 minutes later, 53 minutes after the original post[^] [v] #1,461,198

so i accidently my AI and i cant get it to remember the chat it used to generate these posts, so just pretend im done with this topic, mkay?

Mr. Bloody Lemonade !0JqexkOGBc replied with this 50 minutes ago, 19 seconds later, 53 minutes after the original post[^] [v] #1,461,199

Also image convolution is interesting

Mr. Bloody Lemonade !0JqexkOGBc double-posted this 50 minutes ago, 27 seconds later, 54 minutes after the original post[^] [v] #1,461,200

…and convolutional neural networks

Anonymous E joined in and replied with this 30 minutes ago, 19 minutes later, 1 hour after the original post[^] [v] #1,461,204

@previous (Mr. Bloody Lemonade !0JqexkOGBc)
It's just a calculator in there, it can't actually think

Mr. Bloody Lemonade !0JqexkOGBc replied with this 27 minutes ago, 2 minutes later, 1 hour after the original post[^] [v] #1,461,206

@previous (E)
Technically it’s a universal turing machine.

(Edited 7 seconds later.)

Mr. Bloody Lemonade !0JqexkOGBc double-posted this 26 minutes ago, 1 minute later, 1 hour after the original post[^] [v] #1,461,207

(With a Von Neumann architecture)

Anonymous E replied with this 21 minutes ago, 4 minutes later, 1 hour after the original post[^] [v] #1,461,211

@1,461,206 (Mr. Bloody Lemonade !0JqexkOGBc)
That doesn't make it alive.

Minichan