com.aspose.words

Example:

Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

builder.getParagraphFormat().setStyle(doc.getStyles().get("Heading 1"));
builder.writeln("Hello world!");
builder.insertImage(getImageDir() + "Logo.jpg");

Assert.assertTrue(new File(getImageDir() + "Logo.jpg").length() < 20200);

// When we save the document as an image, we can pass a SaveOptions object to
// select a color mode for the image that the saving operation will generate.
// If we set the "ImageColorMode" property to "ImageColorMode.BlackAndWhite",
// the saving operation will apply grayscale color reduction while rendering the document.
// If we set the "ImageColorMode" property to "ImageColorMode.Grayscale", 
// the saving operation will render the document into a monochrome image.
// If we set the "ImageColorMode" property to "None", the saving operation will apply the default method
// and preserve all the document's colors in the output image.
ImageSaveOptions imageSaveOptions = new ImageSaveOptions(SaveFormat.PNG);
imageSaveOptions.setImageColorMode(imageColorMode);

doc.save(getArtifactsDir() + "ImageSaveOptions.ColorMode.png", imageSaveOptions);

switch (imageColorMode) {
    case ImageColorMode.NONE:
        Assert.assertTrue(new File(getArtifactsDir() + "ImageSaveOptions.ColorMode.png").length() < 156000);
        break;
    case ImageColorMode.GRAYSCALE:
        Assert.assertTrue(new File(getArtifactsDir() + "ImageSaveOptions.ColorMode.png").length() < 84000);
        break;
    case ImageColorMode.BLACK_AND_WHITE:
        Assert.assertTrue(new File(getArtifactsDir() + "ImageSaveOptions.ColorMode.png").length() <= 20000);
        break;
}