Task 1
- 1. Pixel resolution The term resolution is often used for a pixel count in digital imaging, even though American, Japanese, and international standards specify that it should not be so used, at least in the digital camera field. An image of N pixels high by M pixels wide can have any resolution less than N lines per picture height, or N TV lines. But when the pixel counts are referred to as resolution, the convention is to describe the pixel resolution with the set of two positive integer numbers, where the first number is the number of pixel columns (width) and the second is the number of pixel rows (height), for example as 7680 by 4320. Another popular convention is to cite resolution as the total number of pixels in the image, typically given as number of megapixels, which can be calculated by multiplying pixel columns by pixel rows and dividing by one million. Other conventions include describing pixels per length unit or pixels per area unit, such as pixels per inch or per square inch. None of these pixel resolutions are true resolutions, but they are widely referred to as such; they serve as upper bounds on image resolution. According to the same standards, the number of effective pixels that an image sensor or digital camera has is the count of elementary pixel sensors that contribute to the final image, as opposed to the number of total pixels, which includes unused or light-shielded pixels around the edges. Below is an illustration of how the same image might appear at different pixel resolutions, if the pixels were poorly rendered as sharp squares (normally, a smooth image reconstruction from pixels would be preferred, but for illustration of pixels, the sharp squares make the point better). VECTOR AND RASTER IMAGES Raster Graphics (commonly called bitmap images) are made of pixels. Photographs are an example of a bitmap image. They have a fixed resolution and cannot be resized larger without losing quality. Common bitmap file formats end in: .gif .jpg .png .tiff & .bmp Bitmap images typically have much larger file sizes than the same image as a vector graphic so they are often compressed to reduce their size. Bitmap images can be converted from one format to another with programs such as Photoshop. Vector Graphics are images that have been created in a drawing program such as Adobe Illustrator. They use paths to create lines and curves at connecting points called "nodes" to store the graphic's information mathematically. Vector art is resolution independent; whether you enlarge or shrink the image, the output quality is never compromised. This is why logos should always be created in vector art format. Common file formats for vector art used in the commercial printing industry include: .ai .eps & .pdf
- 2. BMP - Short for "Bitmap." It can be pronounced as "bump," "B-M-P," or simply a "bitmap image." The BMP format is a commonly used raster graphic format for saving image files. It was introduced on the Windows platform, but is now recognized by many programs on both Macs and PCs. PNG - which can be pronounced "ping" or "P-N-G," is a compressed raster graphic format. It is commonly used on the Web and is also a popular choice for application graphics. GIF -The letters "GIF" actually stand for "Graphics Interchange Format," but you don't need to remember that. What you should know is that a GIF is a compressed image file format. GIF images use a compression formula originally developed by CompuServe. TIFF - Stands for "Tagged Image File Format." It is graphics file format created in the 1980's to be the standard image format across multiple computer platforms. The TIFF format can handle color depths ranging from 1-bit to 24-bit. JPG - The term actually stands for "Joint Photographic Experts Group," because that is the name of the committee that developed the format. But you don't have to remember that because even computer nerds will think you're weird if you mention what JPEG stands for. Instead, remember that a JPEG is a compressed image file format. PSD - Image file created by Adobe Photoshop, a professional image-editing program; may include image layers, adjustment layers, layer masks, annotation notes, file information, keywords, and other Photoshop-specific elements. PDF - Cross-platform document created by Adobe Acrobat or a program with the Acrobat plug-in; commonly used for e-mail attachments or for saving publications in a standard format for viewing on multiple computers; usually created from another document instead of from scratch; can be edited with Adobe Acrobat, a commercial program. EPS - PostScript (.PS) file that may contain 2D vector graphics, bitmap images, and text; may also include an embedded preview image in bitmap format; can be placed within another PostScript document. AI - Drawing created with Adobe Illustrator, a vector graphics editing program; composed of paths connected by points, rather than bitmap image data; commonly used for logos and print media. COMPRESSION Compression, or "data compression," is used to reduce the size of one or more files. When a file is compressed, it takes up less disk space than an uncompressed version and can be transferred to other systems more quickly. Therefore, compression is often used to save disk space and reduce the time needed to transfer files over the Internet. There are two primary types of data compression: 1. File Compression 2. Media Compression File compression can be used to compress all types of data into a compressed archive. These archives must first be decompressed with a decompression utility in order to open the original file(s). Media compression is used to save compressed image, audio, and video files. Examples of compressed media formats include JPEG images, MP3 audio, and MPEG video
- 3. files. Most image viewers and media playback programs can open standard compressed file types directly. VIDEO CAPTURE DEVICES Converting analog video signals, such as those generated by a video camera, into a digital format and then storing the digital video on a computer's mass storage device. Video capture from analog devices requires a special video capture card that converts the analog signals into digital form and compresses the data. There are also digital video devices that can capture images and transfer them to a computer via a standard serial or parallel interface. OPTIMISING For imagery, optimisation involves choosing a suitable graphic compression format. Compression reduces the image filesize and consequently the time it takes to download and display in a browser. Common compression types include GIF, JPEG and PNG. Many compression formats reduce filesize by removing information from the image (downsampling). For example, the JPEG format reduces overall tonal range to reduce filesize—reducing the tonal range means that highlights and shadows become less pronounced. Reducing the number, and filesize of the images can be a significant issue for websites with large subscriber bases such as news sites. Site owners are charged for the amount of information (data) downloaded from their sites (traffic). The more popular the site and larger the images the greater the traffic costs. STORAGE AND ASSET MANAGEMENT STORAGE AND ASSET MANAGEMENT Digital asset management (DAM) consists of management tasks and decisions surrounding the ingestion, annotation, cataloguing, storage, retrieval and distribution of digital assets. Digital photographs, animations, videos and music exemplify the target areas of media asset management (a sub-category of DAM). Digital asset management systems (DAMS) include computer software and hardware systems that aid in the process of digital asset management. The term "digital asset management" (DAM) also refers to the protocol for downloading, renaming, backing up, rating, grouping, archiving, optimizing, maintaining, thinning, and exporting files. The "media asset management" (MAM) sub-category of digital asset management mainlyaddresses audio, video and other media content. The more recentconcept of
- 4. enterprise content management (ECM) often deals with solutions which address similar features but in a wider range of industries or applications.