| Your time is valuable. It's annoying when you receive | | | | original size, specify the new pixel dimensions, or |
| an image which is too large, too small, or impossible to | | | | specify the absolute size in cm or inches and PPI.If you |
| open.And your customers, suppliers, or friends will hate | | | | don't have either of these programs, you can even |
| you if you do it to them.In this short article, you'll learn | | | | resize in Windows Paint. Choose Image --> Stretch, |
| how to send the right size image, in the right format. It's | | | | and then enter the new size as a percentage of the |
| surprisingly pretty simple, once you know how.Image | | | | original size.It's also worth checking out Irfanview, a |
| formats and sizes seem complicated at first, which is | | | | free image viewer which has been around for years. It |
| why people send images that are the wrong size or | | | | supports every imaginable image format (and then |
| format. But once you understand a couple of basic | | | | some), and includes batch processing (allowing you to |
| principles, you'll be able to easily size any image | | | | resize or otherwise adjust multiple images in one |
| appropriately and send it by e-mail or upload it to a | | | | operation) as well as slide shows and a bunch of other |
| web site.Begin with the end in mindTake Stephen | | | | features.In Windows XP (and possibly some other |
| Covey's advice - start by being clear about your goal. | | | | versions) you can also check the size of your image |
| What is the person to whom you're sending the image | | | | without opening it, by hovering the mouse pointer over |
| going to do with it? Is it just for them to look at on their | | | | the file within Windows Explorer. A box soon pops up |
| computer, or will they need to print it? It makes a big | | | | with all of the details.FormatsOK, the last thing to think |
| difference (the reason is simple, and you'll find out what | | | | about is image format. Not only does this substantially |
| it is in a minute). If the image is to be printed, how | | | | affect the size of the file (in bytes), but also whether |
| big?Pixels and DPIThe answer to the sizing problem | | | | other people can open it!You may have noticed that |
| has to do with pixels. Unless you've been living in a | | | | the most common format is JPEG (which stands for |
| bunker for the last five years, you've probably heard | | | | Joint Picture Experts Group, if you must know), often |
| of them. You may even have an idea what a pixel is: | | | | abbreviated to its three-letter Windows file extension, |
| the smallest element of a digital image - a single | | | | jpg.Most likely your images are already in JPEG format |
| square (rectangle, actually) of a single colour.The | | | | if they have come from a digital camera, although |
| resolution of an image is expressed in PPI, or Pixels | | | | some digital cameras can capture images in TIFF or |
| Per Inch. This is often confused with DPI (Dots Per | | | | RAW formats (which are beyond the scope of this |
| Inch). Strictly speaking, DPI actually relates only to | | | | article).There are a couple of good reasons for the |
| printers, but in practice, the terms are often used | | | | popularity of JPEG. The main one is size. A |
| interchangeably.Resolution essentially determines how | | | | postcard-size, 300 DPI image takes up about 6 MB in |
| large the image can be reproduced. This also depends | | | | it's 'native' format. That's one big e-mail! The same |
| on the output device (computer screen or printer). It's | | | | image saved as a JPEG takes up around one-tenth of |
| important to understand the difference between size | | | | that when saved as a JPEG at a decent quality |
| and resolution. The best way to do this is with an | | | | setting.(The other reason JPEG is a popular format is |
| example...Let's say we have an image which is 300 | | | | because it's extremely widely supported - as well as |
| pixels wide by 150 pixels high. This is the size or pixel | | | | digital cameras, every image editing or viewing |
| dimensions of the image. Simple enough. But here's the | | | | application can handle it - which in turn ensures its |
| tricky bit (so pay attention):The typical computer | | | | popularity!)So by 'compressing' the image, JPEGs take |
| screen size, in pixels, is 1024x768 pixels. The resolution | | | | up a fraction of the space of most other formats. |
| is usually 75 PPI (which means every square inch of | | | | There must be a catch, right? Well, yes and no. Let's |
| screen 'real estate' is 75 pixels wide by 75 pixels | | | | explore a little deeper.JPEG uses an algorithm |
| high).Therefore if we look at our 300 x 150 pixel image, | | | | (mathematical formula) to compress the image. And it |
| it will be four inches (10 cm) wide and two inches (5 | | | | does this essentially by "summarizing" parts of the |
| cm) high. Fine so far. But what if we now want to print | | | | image with less detail in them. In order to do this, and |
| that image?Different printing devices can print at | | | | achieve the incredible ratio of compression which it |
| different resolutions. But generally, for an image to print | | | | does, it actually "throws away" some of the data |
| well, it needs to have a resolution of at least 200 PPI, | | | | (technically, it's known as lossy compression - as |
| or preferably 300. Any less than this, and it will start to | | | | opposed to lossless compression. An example of a |
| look chunky, fuzzy, or pixellated. Or all three!You may | | | | lossless compression algorithm is zip).Well, "throwing |
| have heard of printers which can print at 1200 DPI or | | | | away" bits of your picture doesn't sound too good, |
| more, but this is separate from the size of the image | | | | does it. Actually, it's not as bad as it sounds. When you |
| itself - there's really no need to send a 1200 PPI image | | | | save an image as a jpeg, you're presented with a |
| to your printer.So you can see that our 300 x 150 pixel | | | | choice of quality setting (exactly how this is presented |
| image will only print at a size of about 1 inch (2.5 cm) | | | | varies from program to program). As you would |
| wide by half an inch high. Big difference!By now you're | | | | expect, the higher the quality, the less compression is |
| probably thinking, "OK, enough geeky explanations, how | | | | achieved, and vice versa. However, even at fairly high |
| big should I size my image?!"Here are some guidelines, | | | | quality settings, the amount of compression is still |
| then: | | | | substantial, yet the degradation (in the form of |
| On-screen viewing: height 500 to 700 pixels, width 700 | | | | compression artifacts) is barely perceptible.By the way, |
| to 900 pixelsPrint - 200 to 300 PPI. So for a 4x6" | | | | if you do need to send an image file which is larger |
| (10x15 cm) print, the pixel dimensions should be 800 x | | | | than about 1 or 2 MB, a file transfer service like or is a |
| 1200 at the smallest, or 1200 x 1800 at the largest. | | | | much more elegant way to do it than e-mail. It saves |
| Obviously for a larger print, you need to increase the | | | | clogging up both your own e-mail as well as the |
| pixel dimensions accordingly. | | | | recipient's. All you do is browse to the file on your |
| The good newsMost imaging programs do all the | | | | computer and enter the recipient's e-mail address, and |
| calculations for you in the "resize" function. Here's how | | | | the file transfer service does the rest.Hopefully you're |
| to resize images in the most popular image editing | | | | now ready to give it a try! In summary:1. Know your |
| applications:In Photoshop (including Photoshop | | | | goal2. Resize the image to the appropriate pixel |
| Elements), go to Image --> Resize --> Image Size, | | | | dimensions, if required3. Save in JPEG format with a |
| where you can either specify the new size in pixels; or | | | | reasonably high quality settingNow go ahead and |
| in centimetres or inches. Don't forget to set a suitable | | | | e-mail some pictures around the place!Steven Pam is |
| resolution for your end use (75 PPI for on-screen | | | | the founder of SmartShots Commercial Photography, |
| viewing, 200-300 PPI for print).The procedure for | | | | based in Melbourne, Australia. |
| PaintShop Pro is very similar: Go to Image --> Resize, | | | | He specializes in photographing people, cars, and |
| where you can resize either as a percentage of the | | | | anything to do with aircraft. |