2. Chapter Four Objectives
Understand role of resolution in representation of detail
Show how digital images and details are sharpened and enhanced

3. Proper Sharpness and Detail
Represents sharp focus
Supports image’s details
Avoids evident digital artifacts

4. Digital color specialists are concerned about pixel resolution
When the image is captured
When the image is edited
When the image is output

5. Sharpness and Detail
In digital images, proper sharpness and detail are dependant on
Pixel resolution
Software sharpening filters

6. Pixels Pixel resolution is expressed as PPI, or pixels per inch
The higher the PPI, the more detail can be represented

7. Pixel Creation Total pixel count Pixel resolution of resulting image
Dictated by CCD or CMOS chip, “film” of a digital camera
Pixel resolution of resulting image
Controlled by distribution of captured pixels

8. A scanner’s optics and software set the pixel resolution of an image when it is digitized

9. The number of captured pixels squeezed into a square inch controls the size of individual pixels and dimensions of entire image

10. File Compression
Reduces a file’s size for storage or transmission

11. Resampling
Two forms
Not recommended as it adversely affects image detail

12. Resampling
Reduce an image’s height and width dimensions and throw out pixels in the process
Enlarge an image and create new pixels in the process

13. Anti-Aliasing
Blurs edges along curves and diagonals to reduce the apparent “stair-stepping” effect of square pixels representing non-square features

14. UnSharp Mask
Software sharpening filters “trick” the eye into believing that there is more detail in the image than there really is

15. Edge Definition and Grain
The Unsharp Mask filter enhances edge definition and smoothes non-edge (or grain) areas.
The defined edge created where the black and ivory regions of the scanner casing touch, and where the aqua and ivory regions touch will both respond to USM adjustments.

16. Edge Definition and Grain
An edge is any border created where light and dark regions touch, or differently colored regions touch.
The defined edge created where the black and ivory regions of the scanner casing touch, and where the aqua and ivory regions touch will both respond to USM adjustments.

17. Advanced Sharpening Techniques
Sharpening individual channels or selected areas allows a greater degree of sharpening control

18. Advanced Sharpening Techniques
The Smart Sharpen Filter in Photoshop CS2 confers the ability to split edges for enhanced control