When it comes to extracting a sub image from a webpage using Selenium, I have found a reliable method. First, I capture a screenshot of the entire page and then extract the desired sub-image using the element's coordinates.
Dimension elementDimension = webElement.getSize();
Point elementPoint = webElement.getLocation();
BufferedImage bufferedImageScreenshot = takeScreenshotByAShotRtrnBufferedImage(driver);
BufferedImage bufferedSubImage = bufferedImageScreenshot.getSubimage(elementPoint.x, elementPoint.y,
elementDimension.width, elementDimension.height);
This technique works flawlessly most of the time, but there is an issue with certain websites that have elements which move along as you scroll down the page. These elements can end up covering the element you are trying to extract.
For instance, if you visit https://www.amazon.com/gp/product/B00V7T1YRQ and attempt to extract the sub element .//*[@id='aplus'], you may encounter a result similar to:
Instead of the expected outcome shown here:
The challenge now is how to obtain the desired image without interference from the overlapping element in red.