Digital imaging or digital image acquisition is the creation of digital images, typically from a physical scene. The term is often assumed to imply

Transcription

1 Digital imaging or digital image acquisition is the creation of digital images, typically from a physical scene. The term is often assumed to imply or include the processing, compression, storage, printing, and display of such images.

2 bitmap In computer, a bitmap or pixmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to the similar concept of a spatially mapped array of pixels. Raster images in general may be referred to as bitmaps or pixmaps, whether synthetic or photographic, in files or in memory.

3 raster In computer, a raster image or bitmap is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium. Raster images are stored in image files with varying formats

4 In digital imaging, a pixel (or picture element[1]) is a single point in a raster image.

5 how do you make a pixel? when a digital image is captured: (scanner, camera, etc) the device 'samples' the image by dividing the image area into a grid of even units next it measures/estimates the color & contrast in each of the cells in this grid. this is referred to as sampling. these samples are what we call pixels

6 vector images In computer, a raster image or bitmap is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium. Raster images are stored in image files with varying formats

7 vector images I won t be doing much with vector in this course, but we do stray into it occasionally

8 File Formats It is very important that file extensions, or suffixes, remain intact. The extension assists the computer operating system. It tells the system the type of file and the application to use when opening the file. This is especially important when bringing a file from one operating system to another (such as going from a Mac to a PC). -Burroughs and Mandiberg, Digital Foundations

9 OTHER Non-Graphics you probably already know!.doc or.docx - Microsoft Word document.rtf - Rich Text Format, non-proprietary word processing format.txt - Text only, no formatting

10 .ai - Adobe Illustrator file.eps Encapsulated PostScript - exported Illustrator file.psd - Photoshop document.fla - Flash master file.swf - Shock Wave Format - exported Flash file for the web.html - HyperText Markup Language - a text file written in the language used to create web pages.

11 .pdf - Portable Document Format usually *noneditable publishing format, can have password permissions set to protect who edits.tif or.tiff - Tagged Image File - format for photographs, saved with lossless compression and used for scanning and printing..jpg or.jpeg - Joint Photographic Experts Group - a compressed image file format often used for photographs on the web.gif - Graphic Interchange Format - a compressed image file format often used on the web for logos, design elements, and other with low numbers of colors..png -Portable Network Graphics

12 .pdf Portable Document Format (PDF) is a generic computer term.[citation needed] The best-known PDF implementation is Adobe PDF, a file format created by Adobe Systems in 1993 for document exchange.

13 .tiff or.tif Tagged Image File Format (abbreviated TIFF) is a file format for storing images, including photographs and line art. It is as of 2009 under the control of Adobe Systems TIFF is a flexible, adaptable file format for handling images and data within a single file, by including the header tags (size, definition, image-data arrangement, applied image compression) The ability to store image data in a lossless format makes a TIFF file a useful image archive, because, unlike standard JPEG files, a TIFF file using lossless compression (or none) may be edited and re-saved without losing image quality. Of course this is not the case when using the TIFF as a container holding compressed JPEG. Other TIFF options are layers and pages.

14 .jpg or.jpeg say: jay-peg Joint Photographic Experts Group #lossy compression for photographic images. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. #JPEG is not as well suited for line drawings and other textual or iconic, where the sharp contrasts between adjacent pixels cause noticeable artifacts.

15 .gif sometimes pronounced jif (Thomas loves to annoy you with his pronunciation) lossless compression, supports 256 levels of color # GIFs are suitable for sharp-edged line art (such as logos) with a limited number of colors. favors flat areas of uniform color with well defined edges (in contrast to JPEG, which favors smooth gradients and softer images). # GIFs can be used for small animations and lowresolution film clips. (but there have been advances checkout: cinemagraphs) # In view of the general limitation on the GIF image palette to 256 colors, it is not usually used as a format for digital photography.

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17 .png Portable Network Graphics (PNG) is a bitmapped image format that employs lossless data compression. PNG was created to improve upon and replace GIF (Graphics Interchange Format) as an image-file format not requiring a patent license. It is pronounced /ˈpɪŋ/ [1] or spelled out as P-N-G. The PNG acronym is optionally recursive, unofficially standing for PNG's Not GIF.[2] PNG supports palette-based (palettes of 24-bit RGB colors), greyscale, RGB, or RGBA images. PNG was designed for transferring images on the Internet, not professional, and so does not support other color spaces (such as CMYK). # The PNG format is a popular alternative to GIF images since it uses better compression techniques and does not have a limit of 256 colors, but PNGs do not support animations. The MNG and APNG formats, both derived from PNG, support animations

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19 raw A camera raw image file contains minimally processed data from the image sensor of either a digital camera, or motion picture film scanner, or other image scanner. There are dozens, if not hundreds, of raw formats in use by different models of digital equipment (like cameras or film scanners).

20 native file types.psd this is the photoshop document format. saving as a.psd allows you to go back in and edit all styles and layers. be sure to save you work copies as psd!!!.ai illustrator.fla flash

21 rules* when preparing your images for print stay in the native file types PSD, AI, etc Preparing files for the web. Export JPEG, GIF, BMP, PNG Animations (coming to a class near you soon): GIF * your mileage may vary, caveat emptor, do what you need to complete a project