如何使用 Python 代码在 Appium 中比较图片？

Question

我需要在 iOS 应用程序中比较模板图片。我需要使用什么语法？我找到了很多关于它的信息，但只有 Java 语法。

我在 Mac 上使用 Appium + Python。

Answer 1

我猜您已经使用 get_screenshot_as_base64()（here 文档）检索了模板图像和真实图像（以检查模板）。

那么你可以尝试使用Appium内嵌的OpenCV库来检查两张图片的相似程度，通过调用函数get_images_similarity()（here实现）得到相似度分数两张图片并在上面进行推理。

有关更多详细信息，请查看 this 有用的文章！

Answer 2

我尝试用 OpenCV 库将图片与模板进行比较。我就是这样做的：

将方法添加到 base_page.py。

 def compare_image_with_screenshot(self, image_name: str):
 os.chdir('../src/screenshots/')

 with open(f'{image_name}.png', 'rb') as img:
     first_image = base64.b64encode(img.read()).decode('ascii')
 second_image = base64.b64encode(self._driver.get_screenshot_as_png()).decode('ascii')

 return self._driver.get_images_similarity(first_image, second_image)

在页面对象文件中使用此方法。

 @allure.step('Compare screenshot with template')
 def get_image_comparison_percents(self):
 """
 This method gets screenshot on device with template in repo. Comparison result is percentage of similarity. Test is OK if comparison more than 90%
 """
 result = self.compare_image_with_screenshot(OfflineLocators.offline_stub)
 return result.get('score')

在必要的测试中使用步骤。

@allure.link(url='https://jira.myproject.tech/browse/TEST-1', name='TEST-1 - Offline stub')
@allure.title('Offline stub')
def test_offline_stub(appdriver):

TourActions(appdriver).skip_tour()
Navigation(appdriver).open_my_offline_page()

assert Offline(appdriver).get_page_title_text() == 'Offline'
assert Offline(appdriver).get_image_comparison_percents() > 0.9

所有这一切的结果是我得到了一定比例的图片相似度。它可以是您需要的那个百分比。我的测试没问题。

Answer 3

我无法使用 openCV 库。因为我无法安装opencv4nodejs
您可以尝试使用 npm 模块以这种方式安装它：npm i -g opencv4nodejs 所以，我找到了比较图像的解决方案。您可以使用此代码：

/**
 * Finds the a region in one image that best matches another, smaller, image.
 */
public static int[] findSubImage(BufferedImage im1, BufferedImage im2){
    int w1 = im1.getWidth(); int h1 = im1.getHeight();
    int w2 = im2.getWidth(); int h2 = im2.getHeight();
    assert(w2 <= w1 && h2 <= h1);
    // will keep track of best position found
    int bestX = 0; int bestY = 0; double lowestDiff = Double.POSITIVE_INFINITY;
    // brute-force search through whole image (slow...)
    for(int x = 0;x < w1-w2;x++){
        for(int y = 0;y < h1-h2;y++){
            double comp = compareImages(im1.getSubimage(x,y,w2,h2),im2);
            if(comp < lowestDiff){
                bestX = x; bestY = y; lowestDiff = comp;
            }
        }
    }
    // output similarity measure from 0 to 1, with 0 being identical
    System.out.println(lowestDiff + "output similarity measure from 0 to 1, with 0 being identical");
    Assertions.assertTrue(lowestDiff<0.5);
    // return best location
    return new int[]{bestX,bestY};
}

/**
 * Determines how different two identically sized regions are.
 */
public static double compareImages(BufferedImage im1, BufferedImage im2){
    assert(im1.getHeight() == im2.getHeight() && im1.getWidth() == im2.getWidth());
    double variation = 0.0;
    for(int x = 0;x < im1.getWidth();x++){
        for(int y = 0;y < im1.getHeight();y++){
            variation += compareARGB(im1.getRGB(x,y),im2.getRGB(x,y))/Math.sqrt(3);
        }
    }
    return variation/(im1.getWidth()*im1.getHeight());
}

/**
 * Calculates the difference between two ARGB colours (BufferedImage.TYPE_INT_ARGB).
 */
public static double compareARGB(int rgb1, int rgb2){
    double r1 = ((rgb1 >> 16) & 0xFF)/255.0; double r2 = ((rgb2 >> 16) & 0xFF)/255.0;
    double g1 = ((rgb1 >> 8) & 0xFF)/255.0;  double g2 = ((rgb2 >> 8) & 0xFF)/255.0;
    double b1 = (rgb1 & 0xFF)/255.0;         double b2 = (rgb2 & 0xFF)/255.0;
    double a1 = ((rgb1 >> 24) & 0xFF)/255.0; double a2 = ((rgb2 >> 24) & 0xFF)/255.0;
    // if there is transparency, the alpha values will make difference smaller
    return a1*a2*Math.sqrt((r1-r2)*(r1-r2) + (g1-g2)*(g1-g2) + (b1-b2)*(b1-b2));
}

我找到了 here。它工作得很好，但太慢了。如果你也不会使用openCV，你可以使用这种方式。祝你好运。

如何使用 Python 代码在 Appium 中比较图片？

How to compare a picture in Appium, using Python code?

python

ios

appium