Terms 6 Definitions and QuestionsPresentation Transcript
Terms 6 Definitions and Questions
Pixel, Megapixel, Webcam
Pixel : The basic unit of the composition of an image on a television screen, computer monitor, or similar display.
An abbreviation of the term 'picture element.' A pixel is the smallest picture element of a digital image. Like the fibers of a fabric, individual pixels are too small to notice, but together they make up the whole. The smaller the pixels, the higher the resolution. A display resolution described as being 640x480 has 640 pixels across the screen and 480 down the screen, for a total of 307,200 pixels. The higher the number or pixels, the higher the screen resolution.
Megapixel : The imaging term for an image sensor of one million pixels or more. The higher geometric pixel resolution of these sensors produce higher quality digital photographic images.
Webcam : A camera designed to take digital photographs and transmit them over the Internet or other network.
Pixel, Megapixel, Webcam Q/A
Q: Is a 5 Megapixel camera always better than a 3 Megapixel camera? Why or why not?
A: Yes. See http://www.indiana.edu/~college/msb/webcam.php and http://registrar.iupui.edu/webcam/
Fixed storage is an internal storage medium used by computers. The most common type of fixed storage is an internal hard drive.
Although fixed storage devices can be removed from a computer for reasons such as upgrading or repair, they typically are not removed from the system.
Fixed storage capacities are usually in gigabytes.
Removable storage is a data storage medium that is located outside of the computer.
Removable storage tends to come in three varieties: magnetic (e.g. Zip disc), optical (e.g. CD-R/RW), and solid-state (e.g. Flash memory).
Capacities of removable storage devices run from 1.44 MB for a floppy disc up to multiple gigabytes for external hard drives. Removable storage devices also provide conveniences such as the ability to make back-up copies of data, transfer data between computers, and copy data to give to someone else. Many MP3 players, digital cameras, and PDAs use removable storage.
Q: How do removable storage and fixed storage apply to things like digital cameras?
A: Most cameras now have both. They have a small amount of fixed internal storage, and an expansion slot to accept removable storage media. This allows you to take pictures on fixed storage if you don’t have an expansion card, but to expand the memory if you do.
Removable Storage and Printers
Newer printers designed for digital photo printing have slots for removable media. You can take media with pictures out of the camera, plug it into the printer, and print photos, without even needing a computer.
Digital Photo Printer Some of them also have screens so you can preview the pictures. This one takes 4 types of memory cards: Compact Flash, SD, xD, and Memory Stick.
A form of memory that allows multiple memory locations to be erased or written in one programming operation. It is a form of rewritable memory chip that holds its content without the need of a power supply.
Flash memory gets its name because the microchip is organized so that a section of memory cells are erased in a single action or "flash."
Flash Memory Types
Secure Digital Card - The SD card's nimble, portable data transfer and low battery consumption makes it ideal for high-speed digital cameras, camcorders, MP3s, cell phones, PDAs, and global positioning systems. Interface options include an SD interface or a serial peripheral interface.
Memory Stick - Memory Stick is about the size of a stick of gum and comes in many capacities. Memory Sticks can be used in an array of applications, including video cameras, audio recorders, and computers with a Memory Stick slot.
USB Flash Drive - A USB flash drive is essentially NAND-type flash memory integrated with a USB 1.1 or 2.0 interface used as a small, lightweight, removable data storage device of up to 16 GB. Can be used with most USB memory devices and as a small, portable computer hard drive.
Flash Memory Q/A
Q: These are 3 of the most common types of flash memory cards. Can anyone identify them?
A B C
Flash Memory Q/A
A B C
SD Card Compact Flash Memory Stick
Other Types USB Flash Drive xD Card SmartMedia
Physical Size Comparison
USB Drives (Weird)
Refers to data compression techniques in which some amount of data is lost. Lossy compression technologies attempt to eliminate redundant or unnecessary information . Most video compression technologies, such as MPEG , use a lossy technique.
Lossless compression is a slower and less efficient compression technique, but is often used for spreadsheets or text files where the loss of words or data would cause problems. Also, lossless algorithms are easier to understand.
A file that has been reduced in size to allow faster transferring between computers, or to save storage space. Originated with PKWARE, the technique is widely used and the term is used frequently to describe any compressed file. Some compressed files have the .EXE extension, indicating the file is self-extracting.
A file format used to compress PC computer data into smaller files. Often used to speed up Internet downloads.
Short for t ape ar chive, a UNIX utility that combines a group of files into a single file. The resulting file has a .tar extension . The tar command does not compress files. Frequently, therefore, a tar file is compressed with the compress or gzip commands to create a file with a .tar.gz or .tar.Z extension.
These are comparable to files that have been compressed with WinZIP on a PC platform. Most PC compression utilities, including PKZIP, can open ( untar ) a tar file.
Lossy Compression Q/A
Q: MP3 and WAV are two audio formats. One uses lossy compression and the other uses lossless. Which is which?
A: WAV encoding is lossless. MP3 encoding is lossy. This is why low-bitrate MP3s don’t sound as good as CDs (WAV format). However, WAVs are usually around 10x larger than MP3s, making MP3s or similar compressed formats the choice for portable audio and large collections.
Common ZIP/TAR File Q/A
Q: If I zip a file and then zip it again repeatedly, will it keep getting smaller?
A: No. Eventually you hit a point where the file is as small as it can be and still have all the original data be recoverable. This is because ZIP files are lossless encodings.
Common ZIP/TAR File Q/A
Q: I want to archive a large data file to CD for backup. It’s 1 GB. CDs store 700 MB. When I zip it, it goes down to 850 MB. Am I out of luck for burning this file to CD?
A: No. Most ZIP utilities allow you to make archive files that span multiple disks. So you could store a ZIP file on several floppy disks or CDs. To recreate the file, you will then need all of these disks.
Please put away your notes, take out a sheet of paper and put your name and today’s date on it.
What has higher bandwidth, a T3 or a T1?
The magnetic disks inside of hard drive are known as ________.
Which is bigger, a bit or a byte?
What has higher bandwidth, a T3 or a T1? – a T3
The magnetic disks inside of hard drive are known as _ platters _.
Define VRAM. – Video Random Access Memory
Which is bigger, a bit or a byte? – a byte is 8 bits