How many times is the file size different if you save it as a 256-color drawing and as a monochrome drawing?
How many times is the file size different if you save it as a 256-color drawing and as a monochrome drawing? Screen resolution 1024×768. The file in bmp extension is 1 mb, color depth is 32 bits. How much of the screen will this image take?
1)
In a monochrome image, each point in the image can glow in two colors, such as black or white. To store two states, 1 bit per point is sufficient.
With a 256-color image, each dot can light up to 256 colors. One byte per point is required to store 256 states. If translated into bits, we get 8 bits per point.
This means that the size of a 256-color file is 8 times larger than a monochrome file:
8: 1 = 8 (times)
Answer: 8 times.
2) In one megabyte 1’048’576 bytes:
1Kb = 1024B
1MB = 1024Kb = (1024 * 1024) bytes = 1’048’576 bytes
32 bits or 4 bytes are allocated for one image point (32: 8 = 4).
It turns out that 262’144 pixels of an image with a color of 4 bytes per point can be stored in 1MB:
1’048’576: 4 = 262’144
A total of 786’432 image pixels are lit on a 1024×768 screen:
1024 * 768 = 786’432
The resulting image in 1MB will occupy one third of the screen:
262’144 / 786’432 = 1/3
Answer: 1/3 part.