MULTIMEDIA

By Alexis Aguirre

BITMAP GRAPHICS

Bitmap graphics are images that are composed by pixels.

The higher of the number of pixels in an image, the higher the resolution.

People can use image editors to improve the look of the photo by increasing brightness or correcting a red eye. An example is Adobe Photoshop, which is the choice program for most photographers

Editing Tools

Some editing tools that are available in image editing software:

ailable in image editing software is:

Cropping: which involves taking a subsection of a photograph and removing everything else



Scaling: increasing or reducing the size of a image.

Cloning: process of copying one part of an image into another part of an image. This is often done to remove something from the image, such as a person, by painting over them with the program

Selection Tools: highlights just one part of an image so that alterations are applied to only that are instead of the whole image.

Layers: Allow several images to be 'stacked' on top of each other.

Filters: effects features, examples are adjusting saturation levels and contrast. Color Balance (sometimes called Levels) enhances certain colors, add a color cast, or convert image to black & white. Photographic filters might sharpen an image or blur it. Special effect filter like pixelate or posterize while artistic filters give an appearance to traditional artistic tools like pencil or oil paints.

SOCIAL IMPACTS

With Photo editing software being easy to access, modified photographs have increased. These photos can be edited for the purpose to create special effects, make the photograph more "attractive", bring harm to someone's reputation, or just for fun. This can bring positive effects, but the negative effects are very significant. This is a vastgallery that shows edited images throughout the years, ranging from politics, media, body image and law.

Health & Leisure

For many years magazine companies have changed their images to alter their models appearances. This includes their skin & hair & the most controversial is their body, so they can conform to the stereotypical image of "attractiveness". In the photo above we can see the model was altered to look extremely skinny, to the point where she looks anorexic even. This could have a huge negative impact on women especially the young ones who most of the time seem to have low self-esteem since these magazines are making it seem that reaching this size is possible. To crack down on anorexia in France, politicians even passed a law saying photos need to state when they've been airbrushed.

Here we have a gallery of famous female celebrities that have been photo-shopped to appear more "attractive", which I personally think they look perfectly fine before.

Legal Impacts

In 1994 former American footballer OJ Simpson was on trial of murder of his girlfriend and her friend. TIME Magazine published a magazine with Simpson on the cover where they've adjusted the brightness and contrast to make it darker. Critics argued that this made a disturbing, menacing image of Simpson causing a bias on the people who see it.

Other cases include death of civilian Jean Charles de Menezes.

Political Impacts

Iran altered images of a failed missile firing to make it seem as if all the missiles went off. In this case it can show how even experienced journalists and editors to can be fooled.

Some other examples include John Kerry's 2004 presidential campaign,LA Times front page of British soldiers in Basra, and Adnan Hajj's conflict in Lebanon picture.

Scientific Impacts

Dr. Hwang Woo Suk altered images showing eleven stem cell colonies and was published in the journal Science. Dr. Hwang was later convicted of embezzlement of the government funds he used to conduct the falsified research.

In 2006 a similar case happened with Kaushik Dib, who altered images from his research at University of Missouri. He lost his post at the university

SPOTTING DIGITAL FAKES

Most digital fakes lack common knowledge, others are harder to spot. Cloning tools sometimes have repeated pixels in an image, and when they're not clearly visible a photographic analysis software can detect them. Lighting and shadows can also reveal manipulations.

IMAGE STORAGE

All bitmap images are stored in the computer as a rectangular grid of pixels. The resolution of an image refers to the number of pixels on the grid.

Digital Cameras usually quote the resolution in megapixel - one million pixels. This is total amount of pixels, not width or height.

Bit Depth

(also called color depth) refers to the number of bits used to store each pixel in the image. The higher the bit depth, the more colors an image can contain, but more storage space will be required.

Most common bit depth for photographs is 24-bit also known as true color.

Storage Requirements

If you know the resolution and bit depth of an image, you can calculate its storage requirements: width x height x bit depth.

COMPRESSION

Most file formats use some form of compression to reduce redundant, repeated data in images and reduce the of storage space required. Only a few file formats store data using the uncompressed approach (BMP & TIFF being the two most common examples.

Lossless Compression

In this image there is clearly a lot of repeated data like the color

So instead, for example, of storing it like this:

0,0,0,0,0,0,0,0,2,2,0,0,0,0,0,0,0,0,0,0

It could be stored like this:

8,0,2,2,10

The first number of each pair represents the number of pixels, the second the color of the pixel

The compressed version is 44% the size of the uncompressed and still has not lost any data.

Problems concerning this type of compression mainly lie with photographs since they usually have a lot of colors and shade, making it hard to identify a pixel as one color

Lossy Compression

Sacrifices quality in return for space. Discards the data that 'probably' wont be missed by the viewer. For example, if two adjacent pixels in an image look almost the same in color lossy will make them the exact same color.

Problems with this is that once the data is discarding it can't be retrieved, so the quality loss is permanent.

Compressing Other Data

Any type of file can be compressed to some degree. Common formats got general compression include zip, rar, and 7zip.

PPI & DPI

Pixels Per Inch (PPI) determines how many pixels are displayed in each inch of the output-whether on screen or on paper. This is turn determines the physical size of the output and how sharp it will appear.

Dots Per Inch (DPI) is also known as printer resolution. Refers to the number of ink dots that a printer produces when creating an image.

VECTOR GRAPHICS

Vector graphics are composed of objects rather than pixels, which is why they're sometimes called object oriented graphics. Each object is stored as a series of mathematical equations. They can be scaled as large as required without any loss of quality.

3-D Vector Images

Architects and engineers use Computer Aided Design (CAD) software to create 3-D technical drawings of products in development. This allows product to be viewed in detail before it is created.

Graphics in the Movies

Computer aided imagery (CGI) is often used to create animations or special effects, it is more realistic looking than CAD.

Motion capture is used to capture the shape and movements of actors, like in the photo above.

To improve realism further, textures are often used. Usually it is impossible to create the required level of detail purely with 3-D vectors.

3-D objects are often given properties such as hardness, reflectivity, and smoothness. Lights with specific intensities and colors can be added, and then the scene can be rendered or ray traced, calculating how the light a scene behaves bouncing off of objects and into the virtual 'camera'.

To produce high quality images for images in film or TV, render farms have thousands of computers where the processing will be quicker.

CGI Animation Vs. Traditional Animation

Article on how James Cameron's movie Avatar was made & the process of CGI.

Process of how most Traditional Animations are made.

COMMON MULTIMEDIA FILE FORMATS

Video Formats

  • AVI
  • MOV
  • MP4
  • WMV

Audio Formats

  • AAC
  • FLAC
  • MP3
  • WAV
  • WMA

Image Formats

  • BMP
  • TIF
  • GIF
  • PNG
  • JPEG
  • PSD
  • RAW
  • CR2
  • SVG

DIGITAL AUDIO

Sound is recorded, converted into digital data (digitized), and loaded into audio editing software, where it can be manipulated using a wide range of effects and filters.

The quality of a recorded sound is determined by its sample rate (sampling frequency). The sample rate determines how many times each second a digital sample of the analog data is taken: the more frequent the samples, the closer it'll sound to the original.

Bit rate is the amount of data used to represent each second of audio. Higher bit rates mean there is a larger number of digital values to choose from when taking a sample.

MIDI

Musical Instrument Digital Interface (MIDI) is a communication standard for music devices, computers, and music creation software. MIDI devices have built in recording of different instruments played at different notes & pitches. Contain instructions on how to play these instruments, but not the actual sound.

DIGITAL VIDEO

At their simplest, video editing programs allow video tracks to be cut, removes, rearranged, and allow a sound track to be added.

More advanced video editing software allows a range of effects to be added, such as changing the color balance, brightness, saturation of the video, or adding effects like grain.

Chroma key (green screen or blue screen) effects allow part of a video image to be replaced with another image or video source by removing specific colors. Morphing is sometimes used with this, and it's where a source image is slowly transformed into a second image over a series of frames.

Codecs

To play compressed audio or video data on a computer, a suitable codec is needed

Streaming Media

Streaming media describes video or audio data that is played while it is being downloaded from the Internet, rather than waiting for the entire data to be downloaded before playing commences.

INTELLECTUAL PROPERTY

Intellectual property refers to non-physical creations such as stories, music, works of art, & computer software.

Copyright Law provides protection against use of this intellectual property by unauthorized users.

Fair Use

Fair use allows exceptions to copyright laws under certain limited circumstances.

Educational Far Use only applies in specific circumstances and does not exempt institutions or their students from copyright law.

Enforcing copyright

Preventing copyright infringement can be difficult since copyright laws vary from country to country

Some photographers or illustrators often use watermarking techniques to try and prevent copyright infringement

Digital Rights Management (DRM) how media companies control their films, music, and e-books are distributed and used

Free licenses

Authors can choose to license their work freely

The Creative Commons licenses give creators a standard what to do this while insisting on certain conditions, such as requiring attribution.

The GNU Free Documentation License (GFDL) is a similar license, although is allows no restrictions on the use of work.

You should also always cite your sources to give credit to the user!

DESKTOP PUBLISHING AND WORD PROCESSING

Features

Master pages allow you to change something on that single page and it will do it to the rest of the pages.

Templates provide predefined layouts for creating a variety of document types.

Grouping tools facilitate the management of multiple objects at the same time.

Presentations

Presentation software displays a series of slides on a screen or projector.

People ranging from business workers to teachers use this software to communicate ideas, facts, and opinions.

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