Multimedia World

Date: 8/5/05

Reporter: Zhe Zhang


August 5th was a very busy, but interesting and fun day. First at the beginning of the day, we went to Mount Saint Antonio College for a lecture on Chemistry and global warming. After that, we headed back to California State University Los Angeles for lunch until at one o’clock we went to a lecture about bioinformatics until 2 o’clock. After this, the NASA SHARP apprentices headed to the engineering building for the “Multimedia World” lecture. When we first arrived in the designated classroom, Dr. Lili Tabrizi was there awaiting our arrival. This somewhat caught us by surprise, but she was just there to help remind us and update us on assignments, final projects and reports, NASA SHARP’s future, MTSI, and just an overall talk and question & answer section involving the end of the program, final deliverables, and wrapping things up.

After several minutes, Dr. Jane Dong arrived and we started our lecture on “A Magic World of Multimedia”. We began with a very interesting physical demonstration of a new type of multimedia, the tablet PC. Dr. Dong uses this tablet PC as her regular laptop, but the monitor can also fold over the keyboard before the computer if folded closed so that the length is reduced in a half and the monitor is facing outward. This was an amazing new experience and exposure to new multimedia and technology. However, it became better when she taught us that she can also write on the monitor and on the screen with a special pen. This makes the tablet PC very useful for note-taking, presentations, and demonstrations. As she was showing us the tablet PC, she also set up the computer for her presentation.

After she was ready setting up, she began her Powerpoint presentation about multimedia and its different aspects and intricacies. First of all, what is multimedia? It cis mainly used as a vague, non-specific term referring to the coming together of text, graphics, still and moving images, animation, sounds, and any other place where information can be stored, transmitted, and processed digitally. Then Dr. Dong continues onto the next several slides to further introduce multimedia. She teaches information such as the fact that multimedia relies on digital aspects and comes in interactive and non-interactive types. She reinforced those images through a series of examples of interactive and non-interactive multimedia, along with examples of multimedia. Some were like streaming Internet video, digital cable, and a DVD movie. Multimedia becomes “multi”-media because of the integration of different types of digital information. Text, graphics, image, video, animations, captured (real-life), synthesized (digitally cretead, discrete (does not involve time, i.e.  pictures), and continuous (involves time, i.e. live feed). Captured media means recordings and pictures, while synthesized media means animation, graphics, text, etc.

The text that I’m using to write and that you’re reading right now is digital text that the computer creates when I type in the letters on the keyboard. Just like most parts of multimedia, there are different types and styles of text. There is plain text and then there is rich text. Plain text is unformatted and is in ASICCII code that all have the same size and font. Rich text on the other hand can be formatted with color, font, style, size, etc. Graphics and images, just like text, can have several differences. A graphic is a revisable document that keeps the structural info in digital info and can be regenerated by a computer. An image on the other hand is a two dimension matrix made up of many, many pixels. A pixel is the smallest piece of resolution and equals one bit. There are binary images (one pixel depth), gray-scale (eight pixel depth), and color images (24 pixel depth). The difference between a graphic and image is that a graphic is made up of structural info and a computer while an image has no structural info. The computer would not be able to.

Along with differences in graphics and images, there is also a difference in video and animation. They are made up of images and graphics only being shown for a small amount of time. Video uses moving images and moving pictures, while animation uses moving graphics. Video can be captured or synthesized and has a series of images back-to-back-to-back… and each image is a frame. Animation on the other hand is created by a computer program that takes the graphics and brings them together and moves (changes) the graphics at calculated times.

Of course, sound must be a part of multimedia. It is only one dimension and there is speech vs non-speech sound and natural vs structured sound. First, speech has semantics while non-speech sound doesn’t have semantics. Next, natural sound is an actual sound wave recorded or generated into a digital signal, but structured sound is when sound is synthesized in a symbolic way as like in a MIDI file. After learning all of this about the different aspects of multimedia, our lecture took a break and Dr. Dong prepared her second part of her lecture.

Her next slides began about the important digital aspects that are very important to multimedia. One especially important thing about multimedia is converting analog to digital. This occurs by sampling, then quantization, and finally encoding. In sampling, values of signals are measured, then in quantization, those values are put into a finite set, and encoding finishes the packaging. Another important part is how are the images and colors work together. Each image is made out of basic pixels, which have their own coordinates. Binary images have 1-bit per pixel, while gray-scale (usually 8-bit) and color (24-bit per pixel) have higher bit counts per pixel. In the color pictures, the color space of the colors in multimedia is important. Red, green, and blue (RGB) are the three main colors used to created colors and each pixel in a digital image as three components, one of each RGB. Dr. Dong continued to say that digital audio involves sampling rate of how fast the sound gets analyzed. There can be a certain number of bits per one sample and there are stereo and mono channels. In the sampling rate, it comes in Hertz. So the more hertz there are, the better the quality because there is more sampling, but this results in a bigger file.

So at the end, Dr. Dong concluded her presentation again with the tablet PC and discussed a little about the amazing technology of the present and how we as students can make it better if enter the multimedia, engineering, and/or technology fields. Overall it was a very interesting and informative lecture on some of the things that we see, hear, feel, and interact with everyday. We, as NASA SHARP apprentices, were able to get a better, in-depth look into the huge world of multimedia, which we should strive to understand better and fuller. The Magic World of Multimedia will forever grow and expand better and better.


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