Perhaps one of the concepts which has been the easiest to grasp for me thus far, has been how light is transformed into machine code, then RBG triplets and subsequently stored as data. The process from camera to digitization begins with electricity (as with most things concerning computation). Certain materials in conjunction with chemicals have a reaction when interacting with light, which results in electrical charges. (White p.68, 2007) These charges are processed through a semiconductor, an ADC (analog-to-digital Converter), and then into the microprocessor. (White p.69, 2007) Once the electrons reach the microprocessor, they are transformed into RGB (Red Green Blue) triplets.
Inside each red, blue and green color spectrum is 256 different shades of those colors represented by bits. Within the entirety of the RGB spectrum of colors is 256^3 (16,777,216) different combinations of triplets. (White p.101, 2007)These RGB triplets are formed into an array and stored as data, but before this occurs, an algorithm is run to determine missing color values based on surrounding pixels. Once the array is produced, the data can be stored as either RAW, uncompressed, or lossy compressed files. (White p.112, 2007) One of the most common methods of storing images is as JPEG files or “jpg” which will be discussed in the following paragraph. (White p.112, 2007)
When encoding digital images, standard formats are important for multiple reasons. One of the reasons a standard format like JPEG is so practical, is because of its ability to compress digital files. File compression is essential for the successful and efficient transfer of data over the internet. JPEG takes a digital image, and uses an algorithm which finds pixel colors recurring many times within a digital image, this being the “reference pixel.” (White p.113, 2007) Once all the reference pixels are determined, they are used to limit the file size of an image by compressing unnoticeably unique RGB triples into the standard reference pixel across the entire image. Furthermore, it is possible to control the level of compression in a JPG file to suit the needs of the user. (White p.113, 2007) The standardization of JPEG was critical for future innovations in the file encoding format. As a result of JPEG files being standardized across multiple operating systems and coding languages, it is easier to incorporate the technology in future updates and technological progression.
Questions:
What is RGBA and how does it interact with regular RGB? I understand it has something to do with transparency. Why RGB instead of RYB? Red Yellow and Blue are the primary colors, green is a secondary, so it is confusing to me why green became one of the colors recognized in RGB triplets. What are some examples of non-standard format data types? Can standard formats sometimes have a limiting effect on innovation, as they might reduce the incentives for innovation? What is the difference between hexadecimal systems and binary representations of RGB triplets?
References
Digital images—Computerphile—Youtube. (n.d.). Retrieved February 22, 2021, from https://www.youtube.com/watch?v=06OHflWNCOE
Images, pixels and rgb. (n.d.). Retrieved February 22, 2021, from https://www.youtube.com/watch?v=15aqFQQVBWU
White, R. (2007). How digital photography works (2nd ed). Que.