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Conversion d'une image RVB en image Floyd-Steinberg à l'aide de PHP ou Javascript pour les imprimantes Zebra

Je développe une application PHP basée sur un ordinateur de bureau, dans laquelle nous devons capturer l'image d'une personne et l'imprimer sur l'étiquette à l'aide d'une imprimante Zebra GC420t .__ L'image attendue doit ressembler à l'image ci-dessous.

 enter image description here

Quand j'essaie d'imprimer le, cela donne le résultat comme ci-dessous image.

 enter image description here J'utilise le code suivant pour la conversion de l'image rgb en image dithering à l'aide du code php

 $photo_url="";
if(isset($_GET['photo'])){
  $photo_url=$_GET['photo'];
}

function image2grf($filename='$photo_url', $targetname = 'R:IMAGE.GRF')
{
  $info = getimagesize($filename);
  $im = imagecreatefrompng($filename);
  $width = $info[0]; // imagesx($im);
  $height = $info[1]; // imagesy($im);
  $depth = $info['bits'] ?: 1;
  $threshold = $depth > 1 ? 160 : 0;
  $hexString = '';
  $byteShift = 7;
  $currentByte = 0;
  // iterate over all image pixels
  for ($y = 0; $y < $height; $y++) {
    for ($x = 0; $x < $width; $x++) {
      $color = imagecolorat($im, $x, $y);
      // compute gray value from RGB color
      if ($depth > 1) {
        $value = max($color >> 16, $color >> 8 & 255, $color & 255);
      } else {
        $value = $color;
      }
      // set (inverse) bit for the current pixel
      $currentByte |= (($value > $threshold ? 0 : 1) << $byteShift);
      $byteShift--;
      // 8 pixels filled one byte => append to output as hex
      if ($byteShift < 0) {
        $hexString .= sprintf('%02X', $currentByte);
        $currentByte = 0;
        $byteShift = 7;
      }
    }
    // append last byte at end of row
    if ($byteShift < 7) {
      $hexString .= sprintf('%02X', $currentByte);
      $currentByte = 0;
      $byteShift = 7;
    }
    $hexString .= PHP_EOL;
  }
  // compose ZPL ~DG command
  $totalBytes = ceil(($width * $height) / 8);
  $bytesPerRow = ceil($width / 8);
return sprintf('~DG%s,%05d,%03d,' . PHP_EOL, $targetname, $totalBytes, $bytesPerRow) . $hexString;
}
// Usage:
print "^XA N ^XZ" . PHP_EOL;
print image2grf($photo_url, 'R:SAMPLE.GRF');
//print "^XA^FO20,20^XGR:SAMPLE.GRF,1,1^FS^XZ" . PHP_EOL;

Je connecte mon application et passe des paramètres à l'imprimante à l'aide du code javascript ci-dessous. 

    var available_printers = null;
var selected_category = null;
var default_printer = null;
var selected_printer = null;
var format_start = "^XA^LL200^FO80,50^A0N36,36^FD";
var format_end = "^FS^XZ";
var default_mode = true;

function setup_web_print()
{
    $('#printer_select').on('change', onPrinterSelected);
    showLoading("Loading Printer Information...");
    default_mode = true;
    selected_printer = null;
    available_printers = null;
    selected_category = null;
    default_printer = null;

    BrowserPrint.getDefaultDevice('printer', function(printer)
    {
        default_printer = printer
        if((printer != null) && (printer.connection != undefined))
        {
            selected_printer = printer;
            var printer_details = $('#printer_details');
            var selected_printer_div = $('#selected_printer');

            selected_printer_div.text("Using Default Printer: " + printer.name);
            hideLoading();
            printer_details.show();
            $('#print_form').show();

        }
        BrowserPrint.getLocalDevices(function(printers)
            {
                available_printers = printers;
                var sel = document.getElementById("printers");
                var printers_available = false;
                sel.innerHTML = "";
                if (printers != undefined)
                {
                    for(var i = 0; i < printers.length; i++)
                    {
                        if (printers[i].connection == 'usb')
                        {
                            var opt = document.createElement("option");
                            opt.innerHTML = printers[i].connection + ": " + printers[i].uid;
                            opt.value = printers[i].uid;
                            sel.appendChild(opt);
                            printers_available = true;
                        }
                    }
                }

                if(!printers_available)
                {
                    showErrorMessage("No Zebra Printers could be found!");
                    hideLoading();
                    $('#print_form').hide();
                    return;
                }
                else if(selected_printer == null)
                {
                    default_mode = false;
                    changePrinter();
                    $('#print_form').show();
                    hideLoading();
                }
            }, undefined, 'printer');
    }, 
    function(error_response)
    {
        showBrowserPrintNotFound();
    });
};
function showBrowserPrintNotFound()
{
    showErrorMessage("An error occured while attempting to connect to your Zebra Printer. You may not have Zebra Browser Print installed, or it may not be running. Install Zebra Browser Print, or start the Zebra Browser Print Service, and try again.");

};
  // new Date().toLocaleTimeString('en-US', { hour12: false, 
  //                                            hour: "numeric", 
  //                                            minute: "numeric"});

function sendData(photoURL)
{

    var test;
        $.ajax({
            url: 'db/zpl.php?photo='+photoURL,
            cache: false,
            contentType: false,
            processData: false,
            type: 'GET',
            success: function(data) {
            test=data;
            console.log("From ZPL:"+data);

            }

        });



    var mob="",lap="",other="";
    if($("#emobile").val()==="on"){
        mob="Mobile";
    }

    if($("#elaptop").val()==="on"){
        lap="Laptop";
    }

    if($("#eother").val()==="on"){
        other="Other";
    }

    showLoading("Printing...");
    checkPrinterStatus( function (text){
        if (text == "Ready to Print")
        {
        selected_printer.send("^XA N ^XZ");
        selected_printer.send("~DYE:SAMPLE.GRF,A,GRF,5000,030"+test+",A");          selected_printer.send("^XA^FX^CFA,30^FO10,70^FDVisitorName:"+$("#user").val()+"^FS^FO10,120^FDCompany:"+$("#compName").val()+"^FS ^FO10,170^FDTo Meet:"+$("#toMeet").val()+"^FS ^FO10,220^FDPurpose:"+$("#reason").val()+"^FS ^FO10,270^FDAuthorise^FS ^FO10,320^FDto Carry:"+mob+" "+lap+"^FS^FO250,70^XG R:SAMPLE.GRF,1,1^FS^XZ");
        }
        else
        {
            printerError(text);
        }
    });
};

function checkPrinterStatus(finishedFunction)
{
    selected_printer.sendThenRead("~HQES", 
                function(text){
                        var that = this;
                        var statuses = new Array();
                        var ok = false;
                        var is_error = text.charAt(70);
                        var media = text.charAt(88);
                        var head = text.charAt(87);
                        var pause = text.charAt(84);
                        // check each flag that prevents printing
                        if (is_error == '0')
                        {
                            ok = true;
                            statuses.Push("Ready to Print");
                        }
                        if (media == '1')
                            statuses.Push("Paper out");
                        if (media == '2')
                            statuses.Push("Ribbon Out");
                        if (media == '4')
                            statuses.Push("Media Door Open");
                        if (media == '8')
                            statuses.Push("Cutter Fault");
                        if (head == '1')
                            statuses.Push("Printhead Overheating");
                        if (head == '2')
                            statuses.Push("Motor Overheating");
                        if (head == '4')
                            statuses.Push("Printhead Fault");
                        if (head == '8')
                            statuses.Push("Incorrect Printhead");
                        if (pause == '1')
                            statuses.Push("Printer Paused");
                        if ((!ok) && (statuses.Count == 0))
                            statuses.Push("Error: Unknown Error");
                        finishedFunction(statuses.join());
            }, printerError);
};
function hidePrintForm()
{
    $('#print_form').hide();
};
function showPrintForm()
{
    $('#print_form').show();
};
function showLoading(text)
{
    $('#loading_message').text(text);
    $('#printer_data_loading').show();
    hidePrintForm();
    $('#printer_details').hide();
    $('#printer_select').hide();
};
function printComplete()
{
    hideLoading();
    alert ("Printing complete");
}
function hideLoading()
{
    $('#printer_data_loading').hide();
    if(default_mode == true)
    {
        showPrintForm();
        $('#printer_details').show();
    }
    else
    {
        $('#printer_select').show();
        showPrintForm();
    }
};
function changePrinter()
{
    default_mode = false;
    selected_printer = null;
    $('#printer_details').hide();
    if(available_printers == null)
    {
        showLoading("Finding Printers...");
        $('#print_form').hide();
        setTimeout(changePrinter, 200);
        return;
    }
    $('#printer_select').show();
    onPrinterSelected();
}

function onPrinterSelected()
{
    selected_printer = available_printers[$('#printers')[0].selectedIndex];
}

function showErrorMessage(text)
{
    $('#main').hide();
    $('#error_div').show();
    $('#error_message').html(text);
}

function printerError(text)
{
    showErrorMessage("An error occurred while printing. Please try again." + text);
}

function trySetupAgain()
{
    $('#main').show();
    $('#error_div').hide();
    setup_web_print();
    //hideLoading();
}

Dans la fonction ci-dessous, j'envoie les paramètres nécessaires à l'impression 

        selected_printer.send("^XA^FX^CFA,30^FO10,70^FDVisitorName:"+$("#user").val()+"^FS^FO10,120^FDCompany:"+$("#compName").val()+"^FS ^FO10,170^FDTo Meet:"+$("#toMeet").val()+"^FS ^FO10,220^FDPurpose:"+$("#reason").val()+"^FS ^FO10,270^FDAuthorise^FS ^FO10,320^FDto Carry:"+mob+" "+lap+"^FS^FO250,70^XG R:SAMPLE.GRF,1,1^FS^XZ");

Dans la fonction ci-dessus, les données d'image sont stockées dans ^FO250,70^XG R:SAMPLE.GRF,1,1^FS 

Lorsque j'envoie les données à l'imprimante, celle-ci imprime tout le texte correctement, mais l'image comme indiqué dans la deuxième image, mais l'image attendue doit être imprimée comme indiqué dans la première image. Je suis en mesure d'imprimer la première image si je code la conversion de l'image dans labelary website. Si je clique sur l'image en temps réel et l'imprime, cela donne une deuxième image.

javascriptphpimage-processingzebra-printersdithering
10
bhargav venkatesh

Regardez cette bibliothèque GDIndexedColorConverter c'est une bibliothèque simple qui convertit une image en mode couleur indexée.

require 'GDIndexedColorConverter.php';

// create an image
$image = imagecreatefromjpeg('image.jpg');

// create a Gd indexed color converter
$converter = new GDIndexedColorConverter();

// the color palette
$palette = array(
    array(0, 0, 0),
    array(255, 255, 255),
    array(0, 0, 0),
    array(0, 0, 0),
    array(0, 0, 0)
);

// convert the image to indexed color mode
$new_image = $converter->convertToIndexedColor($image, $palette, 0.25);

// save the new image
imagepng($new_image, 'example_indexed_color.png', 0);

Voici l'entrée:

 enter image description here

Et voici la sortie:

 enter image description here

0
Sherif Salah