The following tips apply to images that must be kept at the highest quality. They may not apply to thumbnail images, images being
used as a background on a web page, etc..
Both JPEG compression and unsharp masking create image artifacts which affect image quality and reduce your ability to enlarge an image, even
when using a special fractal resizing program:
Shoot digital images using the highest quality setting. A "medium" setting should be acceptable, but reduces the ability to enlarge
an image as does sharpening the image in-camera.
Use a "bicubic" or better sampling method when resizing images. Add unsharp masking after
resizing the image, rather than in-camera or before resizing.
Less, or even no sharpening, is better than more. Ideally, sharpening should be applied by the printer or pre-press shop since
it may vary with the printing process and final size of the image.
If you are going to retouch your image, work on it in a lossless image format such as TIFF, PNG, or
Photoshop's native format, which
will also allow you to save extra mask channels, vector masks, and other cool
Save JPEG images at a setting of 11 or 12 in Photoshop. Do not use a lower setting on high resolution images!
Do not use inferior programs like PaintshopPro to save high resolution JPEG images. They may be great for browsing and making thumbnails but
see for yourself the difference between an image saved at PainstshopPro's highest quality setting and
Photoshop's highest quality setting. Look at the difference in the red text and the blue lines...
Here is the same image opened and saved 5 times in Photoshop
with a quality setting of 12...amazing!!! Now,
here's the same image opened and saved from PaintshopPro 5 times.