如何将 TIFF 文件转换为 ASCII Hex 以将 ZPL 发送到 Zebra 打印机

Question

我正在创建一个应用程序以将标签动态打印到联网的 Zebra 打印机。我可以轻松发送文本值，但还需要在标签底部包含徽标。徽标存储在网络位置并且是 tiff 文件。

我正在努力寻找如何做到这一点的好例子。下面的代码会打印出来，但我从文件中收到的返回字符串纯粹是 FFFFF.... 所以我得到的只是一个黑色矩形。

Protected Sub Print()
    Dim IP As String = "172.16.132.92"
    Dim clientSocket As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
    clientSocket.Connect(New IPEndPoint(IPAddress.Parse(IP), 9100))

    Dim bitmapFilePath As String = "\\SomeServer\Advertising\Artwork\Trademarks\Packaging Label Trademarks 8919\Betaplug.tif"
    Dim bitmapFileData As Byte() = System.IO.File.ReadAllBytes(bitmapFilePath)
    Dim fileSize As Integer = bitmapFileData.Length

    Dim bitmapDataOffset As Integer = 0
    Dim width As Integer = 50 '255
    Dim height As Integer = 50 '255
    Dim bitsPerPixel As Integer = 1
    Dim bitmapDataLength As Integer = 400
    Dim widthInBytes As Double = Math.Ceiling(width / 8.0)

    Dim bitmap(bitmapDataLength) As Byte

    For i As Integer = 0 To bitmapDataLength Step 1
        bitmap(i) = bitmap(i) Xor &HFF
    Next

    Dim ZPLImageDataString As String = BitConverter.ToString(bitmap)
    ZPLImageDataString = Replace(ZPLImageDataString, "-", String.Empty)

    Dim ZPL As String = "~DGR:SAMPLE.GRF," & bitmapDataLength & ",018," & _
                        ZPLImageDataString & _
                        "^XA" & _
                        "^F100,200^XGR:SAMPLE.GRF,2,2^FS" & _
                        "^XZ^"
    Dim Label As String = ZPL
    clientSocket.Send(Encoding.UTF8.GetBytes(Label))
    clientSocket.Close()
End Sub

Answer 1

这是我过去解决此问题的方法。此代码是从拖放标签设计器中提取的，因此其中包含一些转换以处理 DPI 的差异，如果不需要，您必须将其删除。但基本过程是获取位图，调整其大小，使其宽度可被 8 整除以进行编码，使其成为单色，因为这是一个开/关像素热敏打印机，将其位转换为十六进制字符串，然后使用 ZPL 的压缩图压缩它（更少我们最终得到一个非常长的字符串，需要永远发送到打印机）。

0.8 阈值只是我发现工作非常可靠的一个数字，它是根据它的黑暗程度决定是否打开/关闭的截止值，您可能需要调整它以满足您的需要.

输入图像为：

使用 Labelary 的在线 ZPL 查看器 (http://labelary.com/viewer.html) 输出：

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim imgZpl As String = TiffToZpl("C:\Users\sooho\Desktop\so.tif", 0.8)
        Debug.Print(imgZpl)
    End Sub

    Public Function TiffToZpl(tiffFilePath As String, grayscaleThreshold As Single) As String

        Dim ms As New System.IO.MemoryStream
        System.Drawing.Bitmap.FromFile(tiffFilePath).Save(ms, System.Drawing.Imaging.ImageFormat.Png)
        Dim bmp = New System.Drawing.Bitmap(ms)

        ResizeBitmapMod8(bmp)
        bmp = Monochrome(bmp, grayscaleThreshold)

        Return BitmapToZpl(bmp, 0, 0)

    End Function

    Private Function BitmapToZpl(ByRef bm As Bitmap, top As Integer, left As Integer) As String
        Dim ret As New System.Text.StringBuilder
        Dim lastHexChar As Nullable(Of Char) = Nothing
        Dim hexCharCount As Integer = 0
        Dim finalHex As New System.Text.StringBuilder
        Dim bitCount As Integer = 0
        Dim binaryCount As Integer = 0
        For r As Integer = 0 To bm.Height - 1
            For c As Integer = 0 To bm.Width - 1
                bitCount += 1
                If Not bm.GetPixel(c, r).Name.Equals("ffffffff") Then
                    Select Case bitCount
                        Case 1 : binaryCount += 8
                        Case 2 : binaryCount += 4
                        Case 3 : binaryCount += 2
                        Case 4 : binaryCount += 1
                    End Select
                End If
                If bitCount = 4 Then
                    If lastHexChar Is Nothing Then
                        lastHexChar = CChar(hexMap(binaryCount))
                        hexCharCount = 1
                    Else
                        If CChar(hexMap(binaryCount)) = lastHexChar Then
                            hexCharCount += 1
                        Else
                            While hexCharCount > 0
                                Dim maxKey As Integer = 0
                                For Each key As Integer In zplHexCompressionMap.Keys
                                    If key <= hexCharCount Then
                                        maxKey = key
                                    Else
                                        Exit For
                                    End If
                                Next
                                finalHex.Append(zplHexCompressionMap(maxKey) & lastHexChar)
                                hexCharCount -= maxKey
                            End While
                            lastHexChar = CChar(hexMap(binaryCount))
                            hexCharCount = 1
                        End If
                    End If
                    bitCount = 0
                    binaryCount = 0
                End If
            Next c
        Next r
        While hexCharCount > 0
            Dim maxKey As Integer = 0
            For Each key As Integer In zplHexCompressionMap.Keys
                If key <= hexCharCount Then
                    maxKey = key
                Else
                    Exit For
                End If
            Next
            finalHex.Append(zplHexCompressionMap(maxKey) & lastHexChar)
            hexCharCount -= maxKey
        End While

        Dim totalBytes As Integer = CInt((bm.Height * bm.Width) / 8)
        Dim byteWidth As Integer = CInt(bm.Width / 8)
        Dim adjustedLeft As Integer = CInt(left * dpiMultiplier_ScreenToPrinter)
        Dim adjustedTop As Integer = CInt(top * dpiMultiplier_ScreenToPrinter)

        ret.Append("^FO" & adjustedLeft.ToString & "," & adjustedTop.ToString)
        ret.Append("^GFA," & totalBytes.ToString & "," & totalBytes.ToString & "," & byteWidth.ToString & ",,")
        ret.Append(finalHex.ToString)
        ret.Append("^FS")

        Return ret.ToString
    End Function

    Private Sub ResizeBitmapMod8(ByRef bm As Bitmap)
        'Resizes a bitmap to its nearest width multiple of 8. Images must be hex-encoded
        'to be send to the printer, and hex encoding requires pairs of 4 bits, so the
        'the image's width must be divisible by 8 or the resulting image will have a black
        'strip down the side once it's decoded by the zpl printer
        If bm.Width Mod 8 <> 0 Then
            Dim width As Integer = bm.Width
            Dim height As Integer = bm.Height
            Dim aspectRatio As Double = width / height
            Dim lowMultiplier As Integer = CInt(Int(width / 8))
            Dim highMultiplier As Integer = lowMultiplier + 1
            Dim diffBelow As Integer = width - (lowMultiplier * 8)
            Dim diffAbove As Integer = (highMultiplier * 8) - width
            If diffBelow < diffAbove Then
                width = lowMultiplier * 8
            Else
                width = highMultiplier * 8
            End If
            height = CInt(width / aspectRatio)
            Dim bmResized As New Bitmap(width, height)
            Dim gfxResized As Graphics = Graphics.FromImage(bmResized)
            gfxResized.DrawImage(bm, 0, 0, bmResized.Width + 1, bmResized.Height + 1)
            bm = bmResized
        End If
    End Sub

    Private Function Monochrome(ByVal bmOriginal As Bitmap, grayscaleThreshold As Single) As Bitmap
        Dim gsBitmap As New Bitmap(bmOriginal)

        Try
            'Convert image to grayscale
            Dim gfxSource As Graphics = Graphics.FromImage(gsBitmap)
            Dim imgAttr As New System.Drawing.Imaging.ImageAttributes
            Dim imgRec As Rectangle = New Rectangle(0, 0, gsBitmap.Width, gsBitmap.Height)
            imgAttr.SetColorMatrix(New System.Drawing.Imaging.ColorMatrix(grayMatrix))
            imgAttr.SetThreshold(grayscaleThreshold)
            gfxSource.DrawImage(gsBitmap, imgRec, 0, 0, gsBitmap.Width, gsBitmap.Height, GraphicsUnit.Pixel, imgAttr)
        Catch ex As Exception
            'image already has an indexed color matrix
        End Try

        'Convert format to 1-index monochrome
        Dim mcBitmap As Bitmap = New Bitmap(gsBitmap.Width, gsBitmap.Height, Imaging.PixelFormat.Format1bppIndexed)
        Dim mcBmData As Imaging.BitmapData = mcBitmap.LockBits(
            New Rectangle(0, 0, mcBitmap.Width, mcBitmap.Height),
            Imaging.ImageLockMode.ReadWrite,
            Imaging.PixelFormat.Format1bppIndexed)
        For y As Integer = 0 To gsBitmap.Height - 1
            For x As Integer = 0 To gsBitmap.Width - 1
                Dim pixelColor As Color = gsBitmap.GetPixel(x, y)
                If pixelColor.Name = "ffffffff" Then
                    Dim index As Integer = y * mcBmData.Stride + (x >> 3)
                    Dim p As Byte = Runtime.InteropServices.Marshal.ReadByte(mcBmData.Scan0, index)
                    Dim mask As Byte = CByte(&H80 >> (x And &H7))
                    p = p Or mask
                    Runtime.InteropServices.Marshal.WriteByte(mcBmData.Scan0, index, p)
                End If
            Next x
        Next y
        mcBitmap.UnlockBits(mcBmData)

        Return mcBitmap
    End Function

    Public Const DPI_Screen As Double = 96
    Public Const DPI_Printer As Double = 203
    Public Const dpiMultiplier_ScreenToPrinter As Double = DPI_Printer / DPI_Screen
    Public grayMatrix()() As Single = {
        New Single() {0.299F, 0.299F, 0.299F, 0, 0},
        New Single() {0.587F, 0.587F, 0.587F, 0, 0},
        New Single() {0.114F, 0.114F, 0.114F, 0, 0},
        New Single() {0, 0, 0, 1, 0},
        New Single() {0, 0, 0, 0, 1}}
    Private hexMap() As String = {
        "0", "1", "2", "3", "4", "5", "6", "7",
        "8", "9", "A", "B", "C", "D", "E", "F"}
    Private zplHexCompressionMap As New SortedDictionary(Of Integer, Char) From {
        {1, "G"c}, {2, "H"c}, {3, "I"c}, {4, "J"c}, {5, "K"c},
        {6, "L"c}, {7, "M"c}, {8, "N"c}, {9, "O"c}, {10, "P"c},
        {11, "Q"c}, {12, "R"c}, {13, "S"c}, {14, "T"c}, {15, "U"c},
        {16, "V"c}, {17, "W"c}, {18, "X"c}, {19, "Y"c}, {20, "g"c},
        {40, "h"c}, {60, "i"c}, {80, "j"c}, {100, "k"c}, {120, "l"c},
        {140, "m"c}, {160, "n"c}, {180, "o"c}, {200, "p"c}, {220, "q"c},
        {240, "r"c}, {260, "s"c}, {280, "t"c}, {300, "u"c}, {320, "v"c},
        {340, "w"c}, {360, "x"c}, {380, "y"c}, {400, "z"c}}

End Class