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Ian · 5th December 2004, 02:48 AM

... but the learning curve can be steep for those who are not very familiar with manipulating digital images.

What Lee has described is a very good way to achieve a small file suitable for displaying on a screen. There are other techniques for sharpening images in Photoshop, including the "Sharpen" and "Sharpen Edges" filters. In all instances where you wish to sharpen the image, the sharpening effects must be applied after resizing the image or adjusting the numbers of pixels per inch. Basically, sharpening effects alter the pixels at boundaries between colors, increasing the contrast and creating an illusion of a sharper image. If you happen to resize the image (or change the pixel count per inch) after applying these effects, the resulting rearrangment of color pixels will degrade the "sharpened" effect.

The sharper the image, the more the image can be compressed without losing clarity. Of course, the sharpening effects need to be balanced asthetically with the changes in contrast and color that occur from applying these effects. There can still be a lot of trial and error ("art") in manipulating simple digital images.

Images produced for screen displays usually are created with resolutions of 72-90 pixels per inch. Most monitors cannot handle higher resolutions, so it is a waste of file space to use higher pixel counts.

Images produced for screen displays are not usually very good for printing because of their low resolution. Most laser printers these days can print 600+ pixels per inch. Good quality digital prints usually need at least 600 pixels per inch, and often higher for first class work. The higher resolution of these images makes for really big files.

One last suggestion. Whenever I am working on a digital image, I always work on a copy of the original. It is sometimes very difficult to undo an applied effect and recover the original image.

Ian.

5th December 2004, 02:48 AM	#9
Ian Vikingsword Staff Join Date: Dec 2004 Location: The Aussie Bush Posts: 4,034	Photoshop is tops ... but the learning curve can be steep for those who are not very familiar with manipulating digital images. What Lee has described is a very good way to achieve a small file suitable for displaying on a screen. There are other techniques for sharpening images in Photoshop, including the "Sharpen" and "Sharpen Edges" filters. In all instances where you wish to sharpen the image, the sharpening effects must be applied after resizing the image or adjusting the numbers of pixels per inch. Basically, sharpening effects alter the pixels at boundaries between colors, increasing the contrast and creating an illusion of a sharper image. If you happen to resize the image (or change the pixel count per inch) after applying these effects, the resulting rearrangment of color pixels will degrade the "sharpened" effect. The sharper the image, the more the image can be compressed without losing clarity. Of course, the sharpening effects need to be balanced asthetically with the changes in contrast and color that occur from applying these effects. There can still be a lot of trial and error ("art") in manipulating simple digital images. Images produced for screen displays usually are created with resolutions of 72-90 pixels per inch. Most monitors cannot handle higher resolutions, so it is a waste of file space to use higher pixel counts. Images produced for screen displays are not usually very good for printing because of their low resolution. Most laser printers these days can print 600+ pixels per inch. Good quality digital prints usually need at least 600 pixels per inch, and often higher for first class work. The higher resolution of these images makes for really big files. One last suggestion. Whenever I am working on a digital image, I always work on a copy of the original. It is sometimes very difficult to undo an applied effect and recover the original image. Ian.