If you want to change the partitions on your computer, you may think that you have to delete them before changing their sizes. Or you want to create an image from your hard disks as backup? Or you reset the Windows password from some users because you forgot them? Or you want to defragment your harddisk but it’s not working properly because some blocks are in use?

Here’s the answer: Hirens Boot CD. Download the ISO file and burn you own boot CD.

Many partition tools, backup tools, recovery tools, testing tools, hard disk tools, password tools, cleaners, optimizers, network tools, process tools, startup tools and antivirus tools. The right tool for every PC user. Also possible on a USB stick.

I am always surprised that many people don’t know how to handle computer images. There are simple rules you have to memorize. A picture consist mainly of the size and the resolution.

Size

In computer language when we define the size we do it in pixels. My PC screen is quite big, 26″ which is about 66 cm. My screen size is 1920 pixels width and 1200 pixels height. Normally we say my screen has the resolution of 1920 x 1200. Strange isn’t it? We use the word “resolution” for the size. Don’t ask me why. If you think about printing out an image, please use centimeters instead of pixels. Here I just explain you about pixels, digital images for computer use only.

• Average size of computer screens: 1024 x 768
• Older standard of computer screen size: 800 x 600
• Getting common now: 1280 x 1024

These sizes are all normal format 4:3, widescreen or 16:9 are also getting common. These sizes are like 1280 x 960 for example.

Resolution

Here we speak of dpi (dots per inch) which is, like the name’s already telling you, the amount of dots or pixels per square inch. Here you have simple three values you have to memorize.

• Computer screen has 72 dpi
• Ink printer has about 300 dpi
• Laser printer has about 600 dpi

Format

You can save your file in many formats. Use “gif” for clip arts with less colors, “jpg” for everything else. The ending “png” is more developed as “jpg” but less common. With “jpg” you can choose quality of the picture, from 0 to 100%. 60% is normally enough for computer screens, 80% is good.

Example

My wife took a picture with her camera. If you open it with an image editor it’s telling you the size is 2736 x 3648 pixels with resolution of 72 dpi. The file size is 2.4 MB. If you wanna print it out, change to 26 x 20 cm and 300 dpi. Now the file is 4 MB, much bigger than before. If you wanna put it on your homepage you take for example 768 x 1024 pixels and 72 dpi. Here 60% quality is enough and then the file size is just 238 KB. More than 10 times smaller than before. 10 times faster for your visitor to see the pictures. This is very important.

Conclusion

It’s important to put your image in the right format. Don’t forget that you can not make your image bigger and bigger. If you take a picture from the internet which has size 100 x 100 pixels, you can not print it out on a A4 paper. You also cannot enlarge an ant to the size of an elephant, don’t you!?