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

pixel is picture element, and corresponds to the monitor resolution on your computer. multiply 640 x 480 to get the pixels = 307,200. If your camera has megapixel CCDs it can obviously make higher resolution pictures if you want (set by menu). 640x480 was an early standard because this was the size of a CCD array for VHS camcorders, and many computer monitors also displayed this size.

bytes corresponds to the amount of memory a picture will take up in your computer hard disk or camera storage card. most cameras use a 3 byte depth for each pixel. this would be 921,600 bytes with out compression. however most cameras offer jpeg compression which produces a smaller file but the actual length depends on the detail and nature of the picture image. a 640x480 picture could be as small as 20 KB or as large as 150 KB after compression.

for 1024x768, thats 786,432 pixels, 2,359,296 bytes, and usually compresses of jpeg of 100 - 200 KB. My Sony Mavica routinely put 10 of this size image on a 1.44 MB floppy disk.

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

1024 X 640

Answer 4

go to howstuffworks to find out