线对 (Line pairs) 是胶片.镜头等电影摄影领域的专用名词. 每毫米线对一般指分辨率的单位,指仪器在一毫米内能分辨出多少对线. 在一定尺度内的可分辨线对数常被用来衡量仪器的空间分辨能力,能分辨的线对数越多,其能分辨每根线的宽度也越小,其分辨能力也越好. 常用到的分辨率单位有线对每毫米(lp/mm).线对每毫弧度(lp/mr).周期每毫米(cy/mm)以及周期每毫弧度(cy/mr). cycles/mm 单位时间长度内出现的波的个数 cycles在这里是指波数,或者叫周期. Produc…

MTF 调制传递函数 评价一个成像系统目前主流的办法主要有三种TV line检测,MTF检测,和SFR检测. MTF是Modulation Transfer Function的英文简称,中文为调制传递函数. 是指调制度随空间频率变化的函数称为调制度传递函数.最开始是为了说明镜头的能力. 在各个摄像头镜头中经常采用MTF描述镜头的MTF曲线,表明镜头的能力.这些曲线是通过理想的测试环境下尽量减少其它系统对镜头的解析力的衰减的情况下测试得出的. MTF是描述不同空间频率下的调制函数. 那么什么是空间…

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A. Sea Battle time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output In order to make the "Sea Battle" game more interesting, Boris decided to add a new ship type to it. The ship consists of…

尽管GNU/Linux并非无所不能,但确实能在很多时候提供免费.开放的解决方案.这两天我想做一个简谱,在网上搜索乐谱排版软件,发现了基于GPL协议的Lilypond软件.只不过Lilypond是用来做五线谱的.幸好,又找到剑桥大学 Silas S. Brown 编写的一个 jianpu-ly.py 脚本,通过调用Lilypond能够最终生成简谱.关于它的详细介绍请看这里. 该脚本支持的简谱语法规则如下: 音阶:1 2 3 4 5 6 7 1' 空拍:0 升.降音:#1 b2 低两个八度.低八度.…

E1. Median on Segments (Permutations Edition) time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output You are given a permutation p1,p2,…,pnp1,p2,…,pn. A permutation of length nn is a sequence suc…

A - A CodeForces - 1042A There are nn benches in the Berland Central park. It is known that aiai people are currently sitting on the ii-th bench. Another mm people are coming to the park and each of them is going to have a seat on some bench out of n…

After the war, the supersonic rocket became the most common public transportation. Each supersonic rocket consists of two "engines". Each engine is a set of "power sources". The first engine has nn power sources, and the second one has…

You are given an integer sequence a1,a2,…,ana1,a2,…,an. Find the number of pairs of indices (l,r)(l,r) (1≤l≤r≤n1≤l≤r≤n) such that the value of median of al,al+1,…,aral,al+1,…,ar is exactly the given number mm. The median of a sequence is the value of…

D. The Wu time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Childan is making up a legendary story and trying to sell his forgery — a necklace with a strong sense of "Wu" to the Kasoura…