Dealing with Bit depth in Photoshop

Value of one pixel in RGB image’s one channel can be described in computer memory value as 256tones or levels. Calculation and storage of color data in the computer memory takes place with ‘8 bits’. 8 bits, bit (binary digit) is the basic and the smallest unit of the computer’s memory.

Bit Depth: Total amount of bits that describes and records color variations and tone values is called as Bit depth. If there’s a requirement of information on tones without color value, 8 bit image with one channel is sufficient for creating a quality image in black and white tone that reproduces all the variations of the tone required for producing a continuous tone. An image with value of 8-bit handling tonal value and variations only is regarded as Grayscale Image.

If 8 bits are required for each of three RGB image’s channels, the result is regarded as 24-bit image (3 x 8). RGB image in Photoshop is not referred as 24-bit image. It is rather regarded as RGB Color that lists the depth of bit in every channel instead of the whole image, for example 8 Bits/Channel. Higher ‘Bit depth’ in images is symbolic of better color potential and accuracy of tonal value, though it’s not viewed sometimes due to the output device limitations. High bit depth images need more memory and data for storage in the file of image (Images of Grayscale mode are considered as 3rd of the RGB image’s size with similar pint size and pixel dimensions). Photoshop’s support is offered for images with 16 Bits/Channel and 32 Bits/Channel value.