使用Imagecomparer，如何排除ToleranceRectangle的中间部分以进行比较？

Question

I am using imagecomparer in my mobile test project and I am able to compare a baseline image to a current screenshot, but the problem comes in where there is a section of the screenshot that is always changing and I would like to exclude that part from being compared. Here is my code:

private bool RunVisualCheck(string screen, string resultsPath, string baseline = "baseline.jpeg", string screenshot = "screenshot.jpeg")
    {
        GetScreenshot(resultsPath + screenshot);

        var baselineImage = Image.FromFile(resultsPath + baseline);
        var actualImage = Image.FromFile(resultsPath + screenshot);
        Image diffImage;
        int ignoreTop = 64;

        var compareArea = new List<ToleranceRectangle>
        {
            new ToleranceRectangle()
            {
                Rectangle = new Rectangle(0,ignoreTop,baselineImage.Width, baselineImage.Height - ignoreTop),
                Difference = new ColorDifference()
            }
        };

        bool goodCompare = ImageComparer.Compare(actualImage, baselineImage, compareArea, out diffImage);

        if (!goodCompare)
        {
            diffImage.Save(resultsPath + "diffImage.jpeg");
        }

        return goodCompare;
    }

private void GetScreenshot(string pathFile)
    {
        System.Threading.Thread.Sleep(2000); // Temp fix to wait until page loads

        var srcFiler = ((ITakesScreenshot)mobileDriver).GetScreenshot();

        srcFiler.SaveAsFile(pathFile, ImageFormat.Jpeg);
    }

Here is an example (not the app being tested) where I would like to exclude the area inside the red rectangle from the overall screenshot from being compared.

Mobile Screenshot Example

Is there an easy way to do this?

Answer 1

Found a better approach than trying to exclude a section from being compared. Thanks to a coworkers suggestion, I am blacking out the sections that do not need comparing and then saving this image. Doing this on the baseline image and the screenshot will have the same effect as excluding it altogether. Here is the code:

Image image = Image.FromFile(@"C:\Screenshots\Screenshot.jpeg");

using (Graphics g = Graphics.FromImage(image))
{
    SolidBrush brush = new SolidBrush(Color.Black);
    Size size = new Size(image.Width, 64);
    Point point = new Point(0, 0);
    Rectangle rectangle;

    rectangle = new Rectangle(point, size);

    g.FillRectangle(brush, rectangle);
}

image.Save(@"C:\Screenshots\Screenshot.jpeg");