A
pixel that has one bit is black and white only.
2x2=4 shades . This pixel will have 4
levels black and white and thus begins to show shades of
gray.Computer imaging concepts 4.
1. Bit-depth (pixels)-color intensity in each pixel.
-Bit depth is the number of bits used to describe each pixel. The greater the number of bits per pixel, the better the image will be.
Pixels are the little squares (40-50um2) that can be seen when a graphics image is enlarged.
A
pixel that has one bit is black and white only.
2x2=4 shades . This pixel will have 4
levels black and white and thus begins to show shades of
gray.X-rays show grayscale only and therefore 8-12 bit processing is sufficient. The human eye can perceive from 25-40 shades of gray, while the computer can differentiate 256.
High color has 65,000 colors and is 16 bit.
True color (RGB color) has 16.7 million colors and is 24 bit.
There is also 32 bit which is over 4 billion colors.
As you increase the color, the resolution will decrease unless you have a good graphics card with lots of memory.
Colors, bit-depth and resolution adjustment is located in the control panel.
2. Resolution.
Resolution is determined by the number of pixels on a screen (dpi-dots per inch). The greater the number, the greater the resolution or the finer the image.
Low resolution-VGA monitors display at 640 x 480 (>307,000) pixels .
SVGA monitors display with a resolution at 800 X 600 pixels and will result in a sharper but smaller image.
XGA monitors display up to 1024 x 768 pixels. The resolutions available depends on the combination of the quality of the graphics card, its memory and the native resolution of the monitor.
Medium resolution-Image display of around 1,280 x 1,024 (1.3 million) to 2160x1440 (3.1 million) pixels will produce good consumer prints, but not good enough for the professional photographer.
SXGA monitors can display a resolution of up to 1,280 x 1,024 (1.3 million) pixels.
Using an image resolution with 1280 x 1024 to output in a peripheral (LCD projector) which has a maximum output resolution of 600 x 800 may result in a final image that has lost pixels and has poor quality. Most new projectors can adjust for this.
High resolution-Image display of around 4096x4096 (about 16 million) pixels are are available and are for professional use.
3. Image size.
It is best to display these images in their true resolution and size to obtain best results. Alter the size, resolution and bit depth of the image at its source or when it is scanned. Image size is directly related to dpi and refers to the physical height and width of the image. A 2 x 2 inch image if scaled up to 4 x 4 requires the addition of more dots to fill in missing ones and, if it is scaled down, will require removal of dots.
Computer monitor resolution is measured by the number of pixels and scan lines.
Scan lines are used to designate resolution in a TV or video monitor. They are a horizontal line of pixels generated by a single horizontal sweep of the beam from a monitor's electron gun. The number of scan lines that make up a frame is the vertical resolution. The TV will have around 400-525 scan lines on a screen. A TV that is monitor quality (Sony) may have up to 700 scan lines. HDTV has a resolution over 1000 scan lines.