2. In This Chapter, you’ll learn on:
Identify processes which lead to degrading of
image resolution and quality.
Utilise imaging software to adjust an image
resolution.
3. Degrading of image resolution and quality
Sharpness is not doubt one of the factor for good
quality image, and despite that lost sharpness can
be restored by sharpening, Oversharpening, on the
other hand can degrade image quality by causing
"halos" to appear near contrast boundaries. Images
from many compact digital cameras are
oversharpened.
4. When an image is capture by the device, noise
arises from the effects of basic physics— the photon
nature of light and the thermal energy of heat—
inside image sensors.
Typical noise reduction (NR) software reduces the
visibility of noise by smoothing the image, excluding
areas near contrast boundaries. This technique
works well, but it can obscure fine, low contrast
detail. As we learn that an image is compose of
dots, called pixels.
The image that you see is created out of millions of
pixels: hence, megapixels. Hence, Megapixels is the
total number of pixels captured by an image
sensor. Therefore a low quality image sensor is also
an factor for the degrading of the image resolution
5. Megapixels and Print Size
This table shows the relationship between camera
megapixels, horizontal and vertical pixels in the image,
and the size of a print at 200 pixels per inch.
MEGAPIXELS IMAGE SIZE (PIXELS) PRINTED SIZE (INCHES) *
2.0 1224 x 1632 6.1 x 8.2
3.0 1536 x 2048 7.7 x 10.2
4.0 1704 x 2272 8.5 x 11.4
5.0 1944 x 2592 9.7 x 13.0
6.0 2048 x 3072 10.2 x 15.4
8.0 2236 x 3504 11.2 x 17.5
* The printed size is determined by dividing the horizontal and
vertical pixels by the pixels per inch.
6. When your image capturing device has more
megapixels, you get large size prints even if you
print with lots of pixels per inch.
You can always print using fewer pixels per inch to
increase the size of your photographs, but image
quality will suffer.
