Bmsc1103
- 1. WEBQUEST- Graphic file formats Yurie Oates Mazhar Iqbal Emily Fraser Vicky Palin
- 2. Raster and Vector Formats Vector graphics are usually made using drawing or illustration packages. They are composed of mathematically defined geometric shapes. Vector graphics can be easily modified within the creating application and are not affected detrimentally by scaling. Because vectors are mathematically defined, scaling simply requires modification of their mathematical locations. Vector graphics typically are saved as EPS format. Raster Images are produced by digital image capture devices: digital scanners or digital cameras, or by pixel editing programs (e.g. Adobe Photoshop). Raster images are composed of a matrix (grid) or bitmap of digital picture elements (pixels). Pixels are squares or rectangles described as black, white, grey or colour. Raster images are saved as TIFF format, but can be saved as EPS. Whereas conversion from vector to raster is easily accomplished, raster conversion to vector is much more difficult and often not possible. Raster images typically are Raster graphics are impacted by scaling.
- 3. Graphic Interchange Format Vs JPEG GIF files incorporate a compression scheme to keep file sizes at a minimum, and they are limited to 8-bit (256 or fewer colours) colour palettes. The GIF file format uses a relatively basic form of file compression that squeezes out inefficiencies in the data storage without losing data or distorting the image. Example:
- 4. Embedded and Linked Graphics
- 5. Colour Palette The Colour Palette consists of two panels: -----The small palette - "Set Colours" panel -----The large palette - "Colours" panel. The small version is always used on monitors smaller than 800 X 600 pixels. The palette, or color table, is a block of bytes defining the colors available for use in an indexed-color image. Each pixel in the bitmap is described by a few bits (1, 4, or 8) representing an index into this color table. That is, the purpose of the color palette in indexed-color bitmaps is to tell the application the actual color that each of these index values corresponds to.
- 6. Lossless Compression Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. Some image file formats, like PNG or GIF , use only lossless compression, while others like TIFF and MNG may use either lossless methods. Lossless compression is used when it is important that the original and the decompressed data be identical, or when no assumption can be made on whether certain deviation is uncritical
- 7. PNG Files Portable network graphics (PNG) is a bitmapped image format that employs lossless data compression. PNG was created to improve upon and replace the gif format as an image-file format not requiring a patent licence. PNG is pronounced “ ping ”. PNG supports palette-based or greyscale images. PNG was designed for transferring images on the internet, not professional graphics, and so does not support other colour spaces.
- 8. .bmp Format Files Using BMP file formatting can be at a disadvantage for the user because it is harder to manipulate the image to fit ones needs. Although there are potentially thousands of individual pixels in each inch of the graphic, they all combine to form one single image. Hence the quality of the image decreases when rescaling it.
- 9. About Flickr ‘’ Flickr - almost certainly the best online photo management and sharing application in the world - has two main goals :’’ 1) We want to help people make their photos available to the people who matter to them . 2) We want to enable new ways of organizing photos . Flickr is a photo sharing website and web services suite, and an online community platform, which is generally considered an early example of a Web 2.0 application. In addition to being a popular Web site for users to share personal photographs, the service is widely used by bloggers as a photo repository. Its popularity has been fueled by its innovative online community tools that allow photos to be tagged and browsed by folksonomic means.
- 10. Sources dx.sheridan.com/advisor/file_formats.html http://webstyleguide.com/graphics/gifs.html http://en.wikipedia.org/wiki/JPEG http:// gis.nic.in/gisprimer/images/vector.gif http://en.wikipedia.org/wiki/BMP_file_format#Color_palette http://en.wikipedia.org/wiki/Portable_Network_Graphics http://www.flickr.com/ http:// en.wikipedia.org/wiki/Flickr