Computer Users’ Group

June 16, 2004

Downloading:

Each download may be different but in general, you choose what you want to download, sometimes you are offered a choice of languages and sites to download from and a place to download it to.

When you are given a choice of sites, choose the one closest to home if you can determine that. Otherwise, choose one that seems to be in English. Once you establish all of that, a dialog box will pop up asking where you want the download to go. Don’t just casually click NEXT. Think about where you want it to go before you even start. You can create a folder called “TEMP” or “DOWNLOADS” to hold all of your downloads.

Downloaded programs are almost always compressed, usually as “ZIP” files. If the file extension is ZIP you’ll need an “UNZIP” program to open it. Windows XP comes with the Extraction Wizard to de-compress ZIP files. For other Windows versions there are programs that you can use such as Winzip or Pkunzip. Some files are executable ZIP files where the decompression engine is included in the file. These have an .EXE extension. Click on OPEN if you left the “save as” dialog box open (a good idea). Otherwise, double click on the file to start the extraction.

In XP, right click on the ZIP file and the Extraction Wizard will lead you through the process. It will ask where you want the files to go. It’s usually appropriate to extract files into the directory that the ZIP file is in. The file will be unzipped, usually into a subdirectory that it will create and then usually an installation program will start. Here you want to designate Program Files as the recipient of the Installed files. Read the available options at each step as not all installations are the same.

 

Saving a .JPG file

When you see an image that you want on the Internet, point to it, right click and select “Save Picture as” and choose the format that you want. But if you want to save it as a .JPG file and that option isn’t available, what do you do?

If you are using Windows XP and use AOL as an ISP then that option may not be available because AOL creates compressed .ART files that can’t be reconverted to JPG in Internet Explorer. The solution is to go to AOL and shut off the compression. However, shutting off the compression will make many AOL pages much slower to load. Johnson-Grace, the company that created .ART claims that the compression can be three times greater than for JPG images, thus a significant speed advantage in surfing AOL pages. Compressed .ART images in AOL can be saved as BMP images and then converted to JPG in any graphics program including Paint in Windows XP or Irfanview (coming up later).

 

Glossary

Here’s where you can find a glossary of computer terms. http://www.htmlgoodies.com/tutors/glossary.html Even better is to type the term into Google and get several answers. Try entering GLOSSARY to find others.

Here are a few definitions.

Script: Script is a file that tells the computer what to do. DOS scripts were called “batch” files. Today most scripts are JAVA scripts or Visual Basic (VB) scripts. This link will take you to a site with 2100 free JAVA scripts so you can see what they do. HTTP://javascript.internet.com

Compression: There are many types of compressed files including ZIP, JPG, and GIF. Compression can be lossless as in .ZIP or lossy as in .JPG. One form of compression is called “run length compression”. Consider a picture with a lot of blue sky. If 100 adjacent pixels all were the same color blue, a bitmap image would produce an 8 bit number for each primary color in that pixel (24 bits or 3 bytes) for a total of 300 bytes. Suppose the computer just said 100 pixels of color blue. The image is then reconstructed when it is displayed or printed. That’s a lot of compression. Compression reduces storage requirements (disk space) and allows data to transmit faster. JPG uses a different algorithm that reduces the detail in areas where there are rapid changes from pixel to pixel. The eye can’t see subtle color changes in small areas and JPEG takes advantage of this. But every time you open, change and re-save it, you lose more detail. This is called lossy compression because the image can never recover the lost detail.

Bitmap: An image where the picture is a direct map from pixel to pixel. Examples are BMP and TIFF. It is not compressed but there can be compressed versions of TIFF images. Images that you are working on should be saved in one of these formats until all corrections and modifications are complete. Then you can convert it to JPG.

 

Florida Links: There are two links listed under LINKS, FLORIDA on Pastfinders’ Web Page that are useful with the rainy season starting.

National Weather Service, Melbourne: The link takes you to the Home Page. From there you can choose to view forecasts, radar, satellite, hydrology, climate and other products. Here’s a radar time-lapse of local weather.

Lightning Tracker: Lightning is the number one weather killer in the US and Orlando is the Lightning Capitol of America. This lightning tracker will show all lightning strikes out to 200 miles from Orlando. Here’s what it looks like.

 

Meta Data: Windows adds some data called Meta Data to all files that it saves. Windows Explorer allows the presentation of Meta Data but it can’t be edited. Open a folder with pictures in it, click on VIEW and select DETAILS. Then you can right-click a column heading and select additional information that you want to show. At the bottom of the selection list is “MORE”. Click that to see a list of all column headings that you can select at one time. You can then left-click a column heading to sort the pictures by the contents of that column.

Image Edit: If you have Picture and Fax Viewer open your images, what program do you use to edit them? Open an image and point to the “Edit Image” icon at the bottom. Right Click on it to get a list of programs that you could use to edit it. The default is Paint and I don’t see a way to change that without changing ths file that will open that type of program.

Image Data: Most digital cameras support the EXIF file system for storing data in an image. Not all graphics programs do, so that data can be lost by opening and saving a file in one of those programs. Before you edit and save an image in a program, test it out by saving an image with a new name and see if it still retains the EXIF data.

Irfanview: This is one of the neatest programs to ever come along. And on top of that, it’s free. Go here: http://www.irfanview.com/ to download a copy. For just a sample of what it can do: It can show thumbnails of your images in sizes from 50x50 to 300x300 pixels. You can save the thumbnails as one large image or as individual images; you can annotate each thumbnail.

You can select a group of images and batch convert the names or the formats. It supports 60 different file formats including image, video and sound files. Download the program, open an image and then look through all of the menus to see what it can do.