Pertemuan 2 : Citra Digital, Sampling, dan Quantization - Part 2 : Sejarah citra digital dan PCD

Summary

The video discusses the history of digital image processing, tracing its origins to the early 1920s when images were transmitted via undersea cables between London and New York for newspaper use. The first digital image, transmitted in 1921, was encoded using telegraph codes and printed with specialized equipment. As technology advanced, image quality improved from 5 to 15 levels of gray by 1929. However, true digital image processing, as defined today, only began with the advent of digital computers. The development of digital imaging was closely tied to the growth of computing and storage capabilities.

Takeaways

• 📜 The early use of digital images started in the newspaper industry.
• 🌍 The first digital image was transmitted between London and New York via an underwater cable in the early 1920s.
• 📰 This system allowed for faster transmission of news images across the Atlantic, reducing delivery time from one week to less than three hours.
• 🖨️ Special printing equipment was used to decode the transmitted image signals and reconstruct them for newspaper printing.
• 🖼️ The first digital image transmission occurred in 1921, using telegraph codes to send and print images.
• ⚙️ Initially, images were encoded in only 5 levels of gray, but by 1929, this was enhanced to 15 levels of gray.
• 👨‍🎨 An example from 1929 is the image of General Pershing, transmitted from London to New York and printed with 15 gray tones.
• 💻 Early digital images were not purely digital by today’s standards, as they did not involve computers in the process.
• 🖥️ The development of true digital image processing began with the rise of digital computers.
• 🔄 The advancement of digital image processing has always depended on the growth of digital computing power and storage capabilities.

Q & A

When did the first digital image transmission take place?

The first digital image transmission took place in the early 1920s, where an image was sent via undersea cable between London and New York.

Which industry was the first to use digital images?

The newspaper industry was the first to use digital images, primarily for transmitting news images across long distances.

What system was used to transmit images in the 1920s?

A system called 'Bradley' was used to transmit images via telegraph codes over cables, enabling faster image transmission for newspapers.

How did the image transmission process work in the early 1920s?

Images were encoded into telegraph codes and transmitted through undersea cables. Specialized printing equipment on the receiving end decoded and printed the images in newspapers.

How long did it take to transmit images across the Atlantic in the 1920s?

The transmission time for images across the Atlantic was reduced from one week to less than three hours, thanks to the Bradley system.

What was the limitation of the early image transmission technology?

Initially, the Bradley system could only transmit images in 5 levels of gray (5 shades of gray), limiting the quality and detail of the images.

How was the image transmission technology improved in 1929?

In 1929, the technology was upgraded to transmit images with 15 levels of gray, resulting in higher-quality images with more tonal variations.

Why are early digital images not considered 'true' digital images?

Early digital images were not considered 'true' digital images because they were transmitted using telegraph codes, without the involvement of digital computers in their processing.

What was the key factor that contributed to the evolution of digital image processing?

The development of digital computers was the key factor that led to the true evolution of digital image processing, as computers enabled the storage and manipulation of digital data.

What are the main technological components involved in modern digital image processing?

The main components are image capture sensors, storage devices, display technologies, and transmission systems capable of handling large amounts of digital image data.