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DIGITAL IMAGES
Two widely used ways to capture or make digital images are either by
scanning existing pictures from negatives, slides, or prints, or by
using a digital camera to take digital pictures.
Basic elements of Digital Photo
Pixel (contraction of picture element, spelled pixel) is the smallest
addressable point of a bitmapped screen that can be independently
assigned color and intensity. Digital pictures are made from many
pixels of varying color and intensity, much in the same way a mosaic
is made from many different colored tiles.
Bitmap is a digital representation of a picture in which all the dots
or pixels making up the picture are rendered in a rectangular grid and
correspond to specifically assigned bits in computer memory.
Resolution is the degree of sharpness of an image displayed on a
computer screen or quality of printed output from a laser printer or
photo or laser typesetter expressed in dots per inch (dpi). Resolution
can also refer to the number of bits per pixel. In printing,
resolution refers to the space between dots in a halftone screen and
is expressed as lines per inch (lpi). Resolution is normally equated
with quality. Usually, the higher the resolution, the higher the
perceived image quality. The higher the resolution of the picture, the
greater the size of the file. However, some image formats, like
JPEG,
compresses image files so you can have high-resolution pictures
smaller file sizes. However files compression may save some space but
quality may change in higher compression. :Some examples of
Digital
JPEG files
  
 Mount
Diablo.
17miles
Hoogly Bridge
Flower
Golden Gate
Reflection
Using a digital camera requires no computer skill but any modification
to the image be it size, tone, filters brightness, color conversion
needs computer experience and knowledge of using software like Adobe
PhotoShop, CorelDraw, Arcsoft Photoimpression, Lview etc. File size
depends a lot on the camera used to take the picture and the type of
file it is saved. It can vary from 80Kb to 20Mb.
The professional digital cameras are aimed at an experienced group of
people who already have solid photographic and computer skills and
want features that take advantage of the advanced equipment.
Pixel to inch conversion
You can download px2in_converter.exe a Macromedia Flash Player to
convert Pixels to Inches/Centimeters
If you have an image you wish to print, you will want to know how big
it will be on paper, and maybe resize or crop it accordingly. Enter
your image width and height in pixels. Enter the dpi (dots per inch),
sometimes called the ppi (pixels per inch). Select "Pixel to
Inch/Centimeter" from the drop-down list. Press the "Convert it!"
button.
The result is shown in the box labeled "Result". Inches/Centimeters to
Pixels
What are the formulae?
Pixels to Inches: inches = pixels / dpi
Inches to Pixels: pixels = inches * dpi
To deal with centimeters, we convert to and from inches (there are
2.54 cm in an inch):
Inches to centimeters: cm = inches * 2.54
Centimeters to inches: inches = cm / 2.54
All figures are rounded to 2 decimal places (you will have to work out
the fractions of inches for yourself).
ANALOG TO DIGITAL PHOTO BY SCANNING
One can save his family or valuable photo collected over years in
Standard Analog Camera or some legal deeds, restoration graphically
some old paintings convert old photos to Color, Sepia or remove
disturbing portion from the photo, change background of the photo.
Though it is time consuming but it is worth save in digital format &
this is a journey that has no end. I've been scanning family photos
for the past eight or nine years and have probably done about 3,500.
First select good Black & white. Sepia or color photographs at least
5"x3.5" inches or post card size. Then you need one good quality high
resolution Scanner & PC with P-IV or P-III processor RAM 512 minimum
and large Hard disk space.
SCAN all photos in high color (24-bit) mode...even those that would
scan as well in grayscale, because many of those pictures are not b/w
but a variety of "colors" depending upon the era during which they
were taken and changes that may have occurred during aging. Newspaper
like photos may be scanned at 72 dpi but standard should be at 300
dpi. If the photograph is good with details then 2000 dpi may be the
choice for minute items.
Save all files as TIFF with appropriate names and write all
collections of these to a data CD or data DVD as a permanent archive.
The reason for saving as TIFF is a losses format while JPEG is a
"loose" format. GIF "compresses" the image by reducing the number of
colors in the image. Make at least one back up copy of each archival
CD or DVD and place it with a remote for safekeeping.
DIGITAL CAMERA
All digital cameras work in a similar fashion. Some digital cameras
may work a little differently but they all contain the basic hardware.
One similarity in all digital cameras is they all have a lens that
projects an image onto a CCD (charge-coupled device). When a picture
is taken software within the camera looks at the image three
times-once each for red, green, and blue then it combines the three
images as one RGB (Red, Green, Blue) image.
Another common feature in all digital cameras is that they have a
place to store the digital image. Pictures are usually stored in EPROM
(Erasable, PROgrammable Memory) microchips. All cameras have their
advantages and disadvantages when it comes to storage.
Most of the cameras have a LCD display screen that allows you to view
all the pictures you have taken. The display screen also allows to
review/delete the pictures you have taken. All digital cameras take
pictures and save the images to a certain resolution. The resolution
size for each picture taken may vary. A better camera will save the
pictures at a higher resolution. Depending on resolution the degree of
sharpness of an image displayed on a computer screen or quality of
printed output from a laser printer or photo or laser typesetter
expressed in dpi (dots per inch).
Digital Camera Photos :
Rainbow
Eagle
Flower Bed
Red Roses
Changi AP Taipei AP
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