dpexpert had assumed that something as simple and essential as resizing digital pictures for transmission on the Internet would be the first thing that any new digi-photographer would learn. Apparently not so.

For the benefit of those who haven’t given the matter a lot of thought here is a step by step guide to preparing pictures for email or for posting to a web site. The advice is offered here in the full realisation that for many, if not most, readers this is akin to teaching Granny to suck eggs.

We opened one of the pictures in PaintShop Pro 9, the fully featured image editor that is a viable alternative to Photoshop at a fraction of the price. The image has a pixel size of 3072 by 2304 and a resolution of 180 dots per inch -- good for making large prints but too cumbersome for the Internet. What’s more the image has not been heavily compressed (it comes from a Canon Powershot S70 7 megapixel camera) so there is room to reduce the file size with further JPEG compression without noticeable loss of quality. JPEG compression is “lossy” but low levels of compression are hard to detect on a PC monitor.

In PaintShop Pro the rough steps to resizing an image are easy to remember. Open the image, select Image from the menu bar and then select Resize. In the Resize dialogue box select Pixels from the resize options.

So far so precise. Now the question is: “How many pixels?” dpexpert has standardised on a vertical pixel count of 640 for our Gallery, letting the horizontal take care of itself. The reasoning is that the average computer monitor is 1024 by 768 pixels. Some image area is lost to menu bars, tool bars and so on, so the available vertical space is not really 768 pixels. And choosing 640 leaves a little room for a frame around the picture and that adds zap to the image.

Just shrinking the pixel dimensions reduces the file size from 2.8MB to 134kb, which is an acceptable size for transmission over a broadband connection. For a dial-up connection an even smaller file is more internet-friendly. But before compressing the file further, let’s gild the picture.

Click on Image in the menu bar and then choose Picture Frame. The dialogue box has a selection of frame styles and the simple mattes are particularly attractive. Once the frame has been applied it only remains to compress the file information.

Click on File, Export, JPEG optimiser and in the dialogue box where it says “Set compression value to…” choose a value. 1 is least compression, 99 is greatest. For our picture, which we wanted to be less than 100kb, we chose a value of 30. The file size was reduced to 96kb. We finished up with a photograph of the right dimensions to display on a PC monitor without scrolling and it is small enough to be uploaded and downloaded quickly.

FOR PHOTOSHOP ELEMENTS ...

Open the image file in Photoshop Elements, then click on Image/Resize/Image Size

Make sure that Resample Image is checked and then highlight and adjust the vertical dimension to 640 pixels.

Once the image is resized click on File/Save For Web and make sure that the file format chosen is JPEG. Adjust the Quality slider and watch the file size under the second version of the image change. As the quality goes up the file size increases, as quality goes down so does file size. The aim here is to get an acceptable compromise between image quality and file size. This involves subjective judgement. Generally speaking a Quality setting of 50 or above will give acceptable results, but higher quality settings will obviously give better results. However, don't get hung up on this. Create three or four versions of the picture at different quality settings above 50 and compare them. It is not easy to pick the difference on a PC monitor.

Photoshop Elements is seriously crippled in one department – the program doesn't have any macro recording facility, called Actions in Photoshop CS. There are a few Frames that can be applied to pictures, found in the Styles and Effects palette, but for interesting mattes it is necessary to create your own.

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