// Excel to PNG in Nodejs 
var aspose = aspose || {};
aspose.cells = require("aspose.cells");
// Create an object of the workbook class and load the source XLSX file.
var wb = new aspose.cells.Workbook("sample.xlsx");
// Instantiate an instance of the ImageOrPrintOptions class to access specific image creation options. 
var imageOptions = new aspose.cells.ImageOrPrintOptions();
// Set Horizontal resolution by calling the setHorizontalResolution method. 
imageOptions.setHorizontalResolution(300);
// Invoke the setVerticalResolution method to set Vertical Resolution. 
imageOptions.setVerticalResolution(300);
// Set the font style by calling the setDefaultFont method. 
imageOptions.setDefaultFont("MS Gothic");
// Call the setOptimized method, set the value to true to optimize the output elements.
imageOptions.setOptimized(true);
// If value of the OnePagePerSheet method is true , all content of one sheet will output to only one page in result. 
imageOptions.setOnePagePerSheet(true);
// Set the image's quality by invoking the setQuality method.
imageOptions.setQuality(100)
// The get(index) method will access the first worksheet in the workbook. 
var Worksheet = wb.getWorksheets().get(0);
// Call the constructor of the SheetRender class for the target sheet.
var sheetRender = new aspose.cells.SheetRender(Worksheet, imageOptions);
// Now, loop through the pages and invoke the toImage method to create image for the sheet.
for (var j = 0; j < sheetRender.getPageCount(); j++) {
    sheetRender.toImage(j,  "ExcelToTIFF" + j + ".tiff");
}