Application Software

Transcription

1 Midterm This Saturday 8:45 10:00 am Venue: Sports Complex Please reach exam venue 15 mins in advance One class in the next week will be cancelled Please bring soft lead pencils, a good eraser and sharpener Exam will be machine graded, so do not leave any stray marks Material: Regular Lectures: till today Lab Lectures: This Thu s lecture will NOT be included Topical Lectures: None Format samples will be posted today There will be negative marking Application Software Reading Assignment: Ch 10 (or Ch 8 if you are using text from market) Sohaib A Khan CS101 - Wk06 - Regular Lecture 1

2 What is Software? Software is the instructions that run on a computer Also called a computer program Two basic types: operating systems and applications Written in a programming language E.g. V-BASIC V (Beginners( All-Purpose Symbolic Instruction Code), C, C++, Java, Fortran Types of Software Distributions Commercial Software Created by a software house (Microsoft, Borland, Adobe), typically ly by large teams of programmers Some commercial software is bundled with hardware Must be purchased Evaluation versions may be free, low cost, or with limited functionality Freeware Software that can be copied and distributed at no cost Author still retains the copyright Open Source Programs distributed with source code Modifications by users are welcome, and this is how software becomes better Shareware Software that can be used in trial period for free, then the author expects a small payment Mostly works on honor system 2

3 Software Versions Commercial Software mostly goes through extensive testing cycles Alpha Release: Preliminary version, not yet ready for use Beta Release: Test version, normally released to consumers, helpful in identifying bugs Often comes with disclaimers Version 1 would typically follow the Beta release Subsequent versions indicate significant upgrades in functionality, as well as lesser bugs Version numbers or revision numbers tell you which release you have Replacing with a new release is called an upgrade Software Bug: A A persistent error in software software not behaving as it should The original software bug Found by Dr Grace Hooper, 1945, in Harvard Mark II Debugging: : Finding and fixing problems Patch: : A small upgrade sent by manufacturer to remove a certain bug from the software Some programmers may not agree that their software has a bug it s-a-feature-not-a- bug! syndrome Software Bugs 3

4 Evaluating Commercial Software Product reviews, e.g. in PC World or PC Magazine, are very useful Trial versions are often available User discussion groups on the web often exist Try Google! Software Suites and Works Programs Software Suites E.g. MS Office, Lotus Several software applications in one package Works Programs E.g. MS Works Not for power users Simplified inexpensive versions Compatible with full versions 4

5 Free Software Many download sites on the web Need to be careful about security when downloading executables Should have updated virus-scan scan software available Open Source software, under GNU license Gnu s Not Unix, Great New Unix,, sponsored by Free Software Foundation Software Piracy Example: How Software Works 5

6 Useful Software Categories Word Processing (Word) Spread Sheets (Excel) Image Editors (Paint, Photoshop IrfanView) Presentation (Powerpoint) Databases (Access) Web Browsers (IExplorer, Firefox) Personal Information Managers (PIMs) (Outlook) Internet (Yahoo Messenger, Skype, GoogleTalk) Utilities (Winzip, Acrobat Reader Google Desktop) Video Editing (Virtual Dub, Primiere) Mathematical Computing (MATLAB, Maple, Mathematica) Programming (VB, VC++, Java) Animation (Flash, Shockwave) Games (Doom, Need for Speed) Security (McAfee, Symantec, Norton Antivirus) Computers and Creativity Computers are an unparalleled tool for creative expression Sketch and paint Touch up photographs Design an automobile Create animated cartoons Create virtual worlds, with people and animals Edit a film Layout a magazine or a poster Record an edit a lecture or a news broadcast Create a multimedia encyclopedia (with movies, sounds, pictures and text) 6

7 Photo Manipulation and Image Editing Software Can touch up photographs Move objects around in a photograph Combine photographs into one Incorporate text Edit image properties (brightness/contrast) Vector vs Bitmap Graphics A vector graphics creation tool Images are represented symbolically using curves etc. Can be zoomed infinitely without loss of quality Cameras, scanners give bitmapped images (consisting of pixels) This image was drawn as a straight line. TrueType fonts are stored in vector format, and hence do not appear jaggy when zoomed 7

8 Vector vs Bitmap Graphics Converting a vector graphic into a bitmap graphic is straight forward This process is called RASTERIZATION, resolution has to be specified Converting a bitmap to a vector is difficult Typically needs a digitization tablet Common Image File Formats Native file formats: Specific to image- editing programs Common formats for photographs BMP TIFF Compressed formats JPEG GIF 8

9 Video Editing Software For example: Adobe Premiere Allows you to merge multiple videos, generate special effects, transitions, filters, sound manipulation etc. Computer Aided Design Software Tools to help design products, buildings, things in 3D E.g. AutoCAD, Google Sketchup 9