HTML, XHTML and CSS All-In-One for Dummies - Andy Harris [52]
♦ Sharpen: The opposite of Blur, the Sharpen filter enhances the contrast between adjacent pixels. When used carefully, it can sometimes improve an image. The Sharpen filter is most effective in conjunction with the Blur filter to remove small artifacts. Figure 6-13 shows the ship image with the Sharpen filter applied.
Figure 6-12: The Blur filter reduces contrast.
Figure 6-13: The Sharpen filter increases contrast.
If you believe crime shows on TV, you can take a blurry image and keep applying a sharpen filter to read a license plate on a blurry image from a security camera. However, it just doesn’t usually work that way. You can’t make detail emerge from junk, but sometimes, you can make small improvements.
♦ Emboss: This filter creates a grayscale image that looks like embossed metal, as shown in Figure 6-14. Sometimes, embossing can convert an image into a useful background image because embossed images have low contrast. You can use the Enhance Colors dialog box to change the gray embossed image to a more appealing color.
♦ Oil Paint: This filter applies a texture reminiscent of an oil painting to an image, as shown in Figure 6-15. It can sometimes clean up a picture and give it a more artistic appearance. The higher settings make the painting more abstract.
♦ 3D Button: This feature can be used to create an image, similar to Figure 6-16, that appears to be a button on the page. This will be useful later when you figure out how to use CSS or JavaScript to swap images for virtual buttons. You can set the apparent height of the image in the filter. Normally, you apply this filter to smaller images that you intend to make into buttons the user can click.
Figure 6-14: Embossing creates a low-contrast 3D effect.
Figure 6-15: Oil Paint makes an image slightly more abstract.
Figure 6-16: The image appears to stick up from the page like a button.
♦ Red Eye Reduction: You use this filter to fix a common problem with flash photography. Sometimes, a person’s eyes appear to have a reddish tinge to them. Unlike the other filters, this one is easier to access from the Image menu. Use the mouse to select the red portion of the image and then apply the filter to turn the red areas black. It’s best not to perform this filter on the entire image because you may inadvertently turn other red things black.
Other effects you can use
Many more effects and filters are available. IrfanView has a few more built in that you can experiment with. You can also download a huge number of effects in the Adobe Photoshop 8BF format. These effects filters can often be used in IrfanView and other image-manipulation programs.
Some effects allow you to explode the image, add sparkles, map images onto 3D shapes, create old-time sepia effects, and much more.
If you want to do even more image manipulation, consider a full-blown image editor. Adobe Photoshop is the industry standard, but Gimp is an open-source alternative (included on this book’s CD-ROM) that does almost as much. See Book VIII, Chapter 4 for more about using Gimp for image processing.
Batch processing
Often, you’ll have a lot of images to modify at one time. IrfanView has a wonderful batch-processing tool that allows you to work on several images at once. I frequently use this tool to take all the images I want to use on a page and convert them to a particular size and format. The process seems a little complicated, but after you get used to it, you can modify a large number of images quickly and easily.
If you want to convert a large number of images at the same time, follow these steps:
1. Identify the original images and place them in one directory.
I find it easiest to gather all the images into one directory,