How many dots and bytes does it to take to represent a 640 x 480 pixel picture?

Question

How many dots and bytes does it to take to represent a 640 x 480 pixel picture?And also 1024 x 768 pixel picture?WHat is calculation to find it?

Answer 1

Umm..multiply 640 by 480? And the file size is different depending on the compression.

Answer 2

A 640 by 480 image is 307200 pixels (640 x 480).

The question is what is the colour depth?

If it is black and white then you only need 1 bit per pixel. So at 8 bits per byte that would be 38400 bytes.

However, most pictures are not black and white. typically they are at 24 bit colour depths. So that is 3 bytes per pixel. So the 640 by 480 image takes up 921600 bytes.

A 1024 by 768 picture at 24 bit colour depth takes up
1024 x 768 x 3 = 2359296 bytes.


This is for uncompressed images. If you use compression, then this can come down by a significant factor, up to a 10th of the size.

However, compression formats like Jpeg do loose some information, so the pictures are not quite as perfect as they started out as. The higher the compression the less perfect the pictures. If you want to calculate how much space a JPEG will take up, then a compression of a 5th would probably give a close answer for a good quality image.

So a 640 by 480, 24 bit colour depth JPEG would be about
180,000 bytes. (640 x 480 x 3 / 5)

A 1024 by 768, 24 bit colour depth JPEG would be about
472,000 bytes

Answer 3

640 x 480 is a VERY small image (VGA quality, like found in toy cameras) Most compact digital cameras today produce images of at least 3072 x 2304 pixels. They can be used to make photographic prints of most any size from 4x6 inches to 11x 14 inches with good clarity and sharpness as long as there has been no camera movement when photographed

Answer 4

Yo. You can have two pictures both 640x480 and they can be different sizes, size depends on the quality and format and colour depth etc.

A 640x480 picture has exactly that 640x480 pixels. The amount you see depends ont the screen you use and the 'pixels per inch' it displays.

You can calculate how much bytes it can be only if they are saved under the same format, colour depth etc.

Answer 5

Depends on the quality

1 byte - 8 bits
2 bytes - 16 bit - 4.915200 Mbytes
3 bytes -24 bits - 40 Mbytes
4 bytes - 32 bits
and so on