Chart to Image with Node.js via C++

Rendering Charts

Aspose.Cells APIs support converting Excel charts to image formats without requiring any additional tools or applications. To provide rendering support, the Chart class exposes toImage(string) methods with a variety of overloads to best suit application requirements.

Rendering Charts to Images

The Chart.toImage(string) method has a variety of overloads to support both simple and advanced rendering. If the application requirement is to render the chart in its default dimensions, we suggest you use the Chart.toImage(string) method as follows.

const path = require("path");
const AsposeCells = require("aspose.cells.node");

// The path to the documents directory.
const dataDir = path.join(__dirname, "data");

// Instantiating a Workbook object
const workbook = new AsposeCells.Workbook();
// Adding a new worksheet to the Workbook
const sheetIndex = workbook.getWorksheets().add();
// Obtaining the reference of the newly added worksheet by passing its index to WorksheetCollection
const worksheet = workbook.getWorksheets().get(sheetIndex);

// Adding sample values to cells
worksheet.getCells().get("A1").putValue(50);
worksheet.getCells().get("A2").putValue(100);
worksheet.getCells().get("A3").putValue(150);
worksheet.getCells().get("B1").putValue(4);
worksheet.getCells().get("B2").putValue(20);
worksheet.getCells().get("B3").putValue(50);

// Adding a chart to the worksheet
const chartIndex = worksheet.getCharts().add(AsposeCells.ChartType.Column, 5, 0, 15, 5);
// Accessing the instance of the newly added chart
const chart = worksheet.getCharts().get(chartIndex);
// Adding Series Collection (chart data source) to the chart ranging from "A1" cell to "B3"
chart.getNSeries().add("A1:B3", true);

// Converting chart to image
chart.toImage(path.join(dataDir, "chartEMF_out.emf"), AsposeCells.ImageType.Emf);

// Converting chart to Bitmap
chart.toImage(path.join(dataDir, "chartBMP_out.bmp"), AsposeCells.ImageType.Bmp);

It is also possible to render the charts to images with advanced settings. Aspose.Cells APIs expose an overload version of the Chart.toImage(string) method that accepts an instance of ImageOrPrintOptions, while allowing you to specify parameters such as resolution, smoothing mode, image format, and so on.

const path = require("path");
const AsposeCells = require("aspose.cells.node");

// The path to the documents directory.
const dataDir = path.join(__dirname, "data");
const filePath = path.join(dataDir, "sample.xlsx");
// Instantiating a Workbook object
const workbook = new AsposeCells.Workbook();
// Adding a new worksheet to the Workbook
const sheetIndex = workbook.getWorksheets().add();
// Obtaining the reference of the newly added worksheet by passing its index to WorksheetCollection
const worksheet = workbook.getWorksheets().get(sheetIndex);

// Adding sample values to cells
worksheet.getCells().get("A1").putValue(50);
worksheet.getCells().get("A2").putValue(100);
worksheet.getCells().get("A3").putValue(150);
worksheet.getCells().get("B1").putValue(4);
worksheet.getCells().get("B2").putValue(20);
worksheet.getCells().get("B3").putValue(50);

// Adding a chart to the worksheet
const chartIndex = worksheet.getCharts().add(AsposeCells.ChartType.Column, 5, 0, 15, 5);
// Accessing the instance of the newly added chart
const chart = worksheet.getCharts().get(chartIndex);
// Adding Series Collection (chart data source) to the chart ranging from "A1" cell to "B3"
chart.getNSeries().add("A1:B3", true);

// Create an instance of ImageOrPrintOptions and set a few properties
const options = new AsposeCells.ImageOrPrintOptions();
options.setVerticalResolution(300);
options.setHorizontalResolution(300);

// Convert chart to image with additional settings
chart.toImage(path.join(dataDir, "chartPNG_out.png"), options);

Supported Chart Types for Rendering

There are a few chart types that are currently not supported for rendering. Such chart types contain N in the Supported column of the table below.

Chart type	Chart sub-type	Supported
Column	Column	Y
	ColumnStacked	Y
	Column100PercentStacked	Y
	Column3DClustered	Y
	Column3DStacked	Y
	Column3D100PercentStacked	Y
	Column3D	Y
Bar	Bar	Y
	BarStacked	Y
	Bar100PercentStacked	Y
	Bar3DClustered	Y
	Bar3DStacked	Y
	Bar3D100PercentStacked	Y
Line	Line	Y
	LineStacked	Y
	Line100PercentStacked	Y
	LineWithDataMarkers	Y
	LineStackedWithDataMarkers	Y
	Line100PercentStackedWithDataMarkers	Y
	Line3D	Y
Pie	Pie	Y
	Pie3D	Y
	PiePie	Y
	PieExploded	Y
	Pie3DExploded	Y
	PieBar	Y
Scatter	Scatter	Y
	ScatterConnectedByCurvesWithDataMarker	Y
	ScatterConnectedByCurvesWithoutDataMarker	Y
	ScatterConnectedByLinesWithDataMarker	Y
	ScatterConnectedByLinesWithoutDataMarker	Y
Area	Area	Y
	AreaStacked	Y
	Area100PercentStacked	Y
	Area3D	Y
	Area3DStacked	Y
	Area3D100PercentStacked	Y
Doughnut	Doughnut	Y
	DoughnutExploded	Y
Radar	Radar	Y
	RadarWithDataMarkers	Y
	RadarFilled	Y
Surface	Surface3D	N
	SurfaceWireframe3D	N
	SurfaceContour	N
	SurfaceContourWireframe	N
Bubble	Bubble	Y
	Bubble3D	N
Stock	StockHighLowClose	Y
	StockOpenHighLowClose	Y
	StockVolumeHighLowClose	Y
	StockVolumeOpenHighLowClose	Y
Cylinder	Cylinder	Y
	CylinderStacked	Y
	Cylinder100PercentStacked	Y
	CylindricalBar	Y
	CylindricalBarStacked	Y
	CylindricalBar100PercentStacked	Y
	CylindricalColumn3D	Y
Cone	Cone	Y
	ConeStacked	Y
	Cone100PercentStacked	Y
	ConicalBar	Y
	ConicalBarStacked	Y
	ConicalBar100PercentStacked	Y
	ConicalColumn3D	Y
Pyramid	Pyramid	Y
	PyramidStacked	Y
	Pyramid100PercentStacked	Y
	PyramidBar	Y
	PyramidBarStacked	Y
	PyramidBar100PercentStacked	Y
	PyramidColumn3D	Y
BoxWhisker	BoxWhisker	Y
Funnel	Funnel	Y
ParetoLine	ParetoLine	Y
Sunburst	Sunburst	Y
Treemap	Treemap	Y
Waterfall	Waterfall	Y
Histogram	Histogram	Y
Map	Map	N

If you try to render the non‑supported chart types to an image or PDF, you may end up with zero‑sized images or a blank PDF.

Advanced topics

• Convert Chart to PDF