Selenium WebDriver/Firefox|Chrome/Java How to disable image loading

FireFox

FirefoxOptions options = new FirefoxOptions();
options.addPreference("permissions.default.image", 2);
WebDriver driver = new FirefoxDriver(options);

The clue found in docs

for setting custom preferences we recommend using the prefs entry instead of passing a profile.

OR

DesiredCapabilities capabilities = new DesiredCapabilities();
FirefoxProfile profile = new FirefoxProfile();
profile.setPreference("permissions.default.image", 2);
capabilities.setCapability("firefox_profile", profile);
WebDriver driver = new FirefoxDriver(capabilities);

Chrome

HashMap<String, Object> images = new HashMap<String, Object>();
images.put("images", 2);
HashMap<String, Object> prefs = new HashMap<String, Object>();
prefs.put("profile.default_content_setting_values", images);
ChromeOptions chrome_options =new ChromeOptions();
chrome_options.setExperimentalOption("prefs", prefs);
DesiredCapabilities chromeCaps = DesiredCapabilities.chrome();
chromeCaps.setCapability(ChromeOptions.CAPABILITY, chrome_options);
WebDriver driver = new ChromeDriver(chromeCaps);