You cannot access file under a package folder. So put them under assets folder like; /src/main/assets/logo/SUB_DIR/FILENAME.png
Then you can access them getContext().getResources().getAssets().open('logo/SUB_DIR/FILENAME.png')
To check if file exists on asset folder use the following code;
private boolean fileExists(String folder, String fileName) {
    try {
        String[] files = getResources().getAssets().list(folder);
        for(String file : files) {
            if(file.equals(fileName)) {
                return true;
            }
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
    return false;
}
Call that method as follows
img = (ImageView) findViewById(R.id.imgSDCard);
if(fileExists("logo/sub", "sd_card_enable.png")) {
        // asset folder has file
        try {
            img.setImageDrawable(Drawable.createFromStream(getAssets().open("logo/sub/sd_card_enable.png"), "sd_card_enable.png"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
Copy your files into the assets folder like following picture; 
(logo is a DIR, and sub is a DIR inside logo)
