dpi、CMYB和bit 是什麼？

Question

我想問有關dpi的問題，為何網站圖片的設定多數是dpi 72？

「1024 x 768px dpi 72」 和 「1024 x 768px dpi 300」的分別是什麼？

何謂CMYB？

儲存bmp格式的圖片時出現的8bit、24bit、32bit等又是什麼？

更新:

sorry, 延長發問， 還是不太明白bit到底是什麼！

Answer 1

最愛解答

dpi = Dot Per Inch

在一吋內可以排列多少點,

通常用於打印機或Monitor(PPI), 點越多, 就表示它的Resolutoin 越高

The magical 72 comes from an old Apple machine whose physical resolution was 72 pixels over 1 inch of screen. This was useful because there's 72 postscript points in an inch, so 1pt on screen was 1px. Which meant that documents you saw on screen @ 100% were the same size as that document in real life.

CMYB = Cyan, Magenta, Yellow and Black

這是四色打印, 首三色可以混出所有色, 當然打印全張黑色時, 就用黑色

1 Bit = 0 or 1

2 bits = 2^2

8 bits = 2^8

24 bits = 2^24

32 bits = 2^32

The higher number of bit, you can present the bit map more precise.