通过POS打印机和图像打印向外国人开帐单

Question

我正在尝试创建一个原型来将文本文件的位图数据打印到支持LAN的epson pos打印机TM-T88V.

虽然我没有问题发送文本和文本格式说明,我不明白,我必须做什么,让我的打印机打印Arecibo消息的数据.

前几行:

00000010101010000000000
00101000001010000000100
10001000100010010110010
10101010101010100100100
00000000000000000000000
00000000000011000000000
00000000001101000000000
00000000001101000000000
00000000010101000000000
00000000011111000000000
00000000000000000000000
11000011100011000011000
10000000000000110010000
11010001100011000011010
11111011111011111011111
00000000000000000000000
00010000000000000000010
00000000000000000000000
00001000000000000000001

该消息有73行和23列,产生1679个图像元素.每个元素由1表示黑色或0表示为白色,应打印为8x8(或16x16)点的正方形.结果会导致

Arecibo消息http://www.satsig.net/seti/message-to-gliese-581.gif

从打印机的规格:

虽然 - 正如我所说 - 连接和发送到打印机是没有问题的,我只是不明白,这个指令想告诉我什么.在Arecibo消息的情况下会是什么

我必须向打印机发送什么号码？我需要发送每个点吗？什么nL, nH specify the number of dots of the image data in the horizontal direction as (nL + nH × 256).意思？

这是我用于原型设计的简单Python程序:

# -*- coding: utf-8 -*-
import struct
import socket

def sendInstructions(mySocket,l):
    for x in l:
        mySocket.send(struct.pack('h', *[x]),1)


def emphasizeOn(mySocket):
    sendInstructions(mySocket,[27,33,48])


def emphasizeOff(mySocket):
    sendInstructions(mySocket,[27,33,0])


def lineFeed(mySocket,number):
    for i in range(number):
        sendInstructions(mySocket,[0x0a,])


def paperCut(mySocket):
    sendInstructions(mySocket,[29,86,0])

def sendText(mySocket,string):
    mySocket.send(string.encode('UTF-8'))


def main():
    mySocket = socket.socket ( socket.AF_INET, socket.SOCK_STREAM )
    mySocket.connect(('192.168.1.15',9100))    


    lines = ["Hello,","World!"]
    emphasizeOff(mySocket)
    lineFeed(mySocket,2)
    for l in lines: 
        if lines.index(l) == 0:
            emphasizeOn(mySocket)
        else:
            emphasizeOff(mySocket)

        sendText(mySocket,l)
        lineFeed(mySocket,2)

    lineFeed(mySocket,4)
    paperCut(mySocket)

    mySocket.close()

if __name__=="__main__":
    main()

Answer 1

此命令一次生成一个图像的水平条带.条带高8或24点,具体取决于m的值.

nL和nH是整数的低字节和高字节,指定水平条带的点的宽度.该宽度计算为nL + nH*256,因此如果您希望图像宽度为550点,则nH = 2且nL = 38.

参数d是位图数据; 如果图像条是8点高,那么每个字节代表条带中的一列.如果条带是24点高,那么三个字节代表一列.

所以,假设你有一个WxH numpy数组的int,1或0,你会:

data = np.zeros((W, H), dtype=np.ubyte)
## (fill in data here)

## Use m=33 since this is apparently the only mode with 
## square pixels and also the highest resolution 
## (unless it prints too slowly for your liking)
m = 33

nH = W // 256  ## note this is integer division, but SO's 
               ## syntax hilighting thinks it looks like a comment.
nL = W % 256

## Divide the array into sections with shape Wx24:
for n in range(data.shape[1] // 24):
    ## Note that if the image height is not a multiple of 24, 
    ## you'll have to pad it with zeros somehow.

    strip = data[:, n*24:(n+1)*24]

    ## Convert each strip into a string of bytes:

    strip = strip.reshape(W, 3, 8)
    bytes = (strip * (2**np.arange(8)[np.newaxis, np.newaxis, :])).sum(axis=2) # magic
    byteString = bytes.astype(np.ubyte).tostring()

    ## Send the command to POS