Extracting Images from Presentation shapes

Images are often added to shapes and also frequently used as slides' backgrounds. The image objects are added through ImageCollection, which is a collection of PPImage objects.

This article explains how you can extract the images added to presentations.

To extract an image from a presentation, you have to locate the image first by going through every slide and then going through every shape. Once the image is found or identified, you can extract it and save it as a new file.

function extractImages() {
    const folderPath = "./";
    const pres = new aspose.slides.Presentation(folderPath + "ExtractImages.pptx");
    let img = null;
    let backImage = null;

    let slideIndex = 0;
    let imageType = 0;
    let ifImageFound = false;

    for (let i = 0; i < pres.getSlides().size(); i++) {
        slideIndex++;
        let sl = pres.getSlides().get_Item(i);

        if (sl.getBackground().getFillFormat().getFillType() === aspose.slides.FillType.Picture) {
            backImage = sl.getBackground().getFillFormat().getPictureFillFormat().getPicture().getImage();
            imageType = getImageTType(backImage);

            const imagePath = folderPath + "backImage_Slide_" + slideIndex + "." + imageType;
            saveImage(backImage, imagePath, imageType);
        } else if (sl.getLayoutSlide().getBackground().getFillFormat().getFillType() === aspose.slides.FillType.Picture) {
            backImage = sl.getLayoutSlide().getBackground().getFillFormat().getPictureFillFormat().getPicture().getImage();
            imageType = getImageTType(backImage);

            const imagePath = folderPath + "backImage_LayoutSlide_" + slideIndex + "." + imageType;
            saveImage(backImage, imagePath, imageType);
        }

        for (let j = 0; j < sl.getShapes().size(); j++) {
            let sh = sl.getShapes().get_Item(j);

            if (java.instanceOf(sh, "com.aspose.slides.IAutoShape")) {
                let ashp = sh;
                if (ashp.getFillFormat().getFillType() === aspose.slides.FillType.Picture) {
                    img = ashp.getFillFormat().getPictureFillFormat().getPicture().getImage();
                    imageType = getImageTType(img);
                    ifImageFound = true;
                }
            } else if (java.instanceOf(sh, "com.aspose.slides.IPictureFrame")) {
                let pf = sh;
                img = pf.getPictureFormat().getPicture().getImage();
                imageType = getImageTType(img);
                ifImageFound = true;
            }

            if (ifImageFound) {
                const imagePath = folderPath + "backImage_Slide_" + slideIndex + "_Shape_" + j + "." + imageType;
                saveImage(img, imagePath, imageType);
            }
            ifImageFound = false;
        }
    }
}

function getImageTType(image) {
    let imageContentType = image.getContentType();
    imageContentType = imageContentType.substring(imageContentType.indexOf("/") + 1);
    imageContentType = imageContentType.substring(imageContentType.indexOf("-") + 1);
    return imageContentType;
}

function capitalize(str) {
    if (!str || str.length <= 1) return str;
    return str.charAt(0).toUpperCase() + str.slice(1);
}

function saveImage(image, path, imageType) {    
    var ImageFormatClass = java.import('com.aspose.slides.ImageFormat');
    let imageTypeValue = java.callStaticMethodSync("com.aspose.slides.ImageFormat", "getValue", ImageFormatClass.class, capitalize(imageType));
    
    image.getImage().save(path, java.newInstanceSync("java.lang.Integer", imageTypeValue.longValue));
    console.log(`Image saved to ${path}`);
}