Question

我想在C＃winForms应用程序上显示一个Image，但质量只有50％，是否可以使用标准的Picturebox？

也许可以通过编程方式将图像调整为50％，然后将其拉伸到Picturebox？

Image img = Image.FromFile(imgFile)

**在此处调整图片大小，或者执行其他操作**

pictureBox.Image = img;
pictureBox.SizeMode = PictureBoxSizeMode.StretchImage;

Answer 1

您可以通过以下功能

更改图片的质量

$scope.arealist = [];

$http.get('arealist.json').success(function (response) {
    $scope.arealist = _.map(response, function (data) {
        return data.area_name;
    });
});

在照片框中指定50％质量图像后，

private void VaryQualityLevel()
{
    // Get a bitmap.
    Bitmap bmp1 = new Bitmap(@"c:\TestPhoto.jpg");
    ImageCodecInfo jgpEncoder = GetEncoder(ImageFormat.Jpeg);

    // Create an Encoder object based on the GUID
    // for the Quality parameter category.
    System.Drawing.Imaging.Encoder myEncoder =
        System.Drawing.Imaging.Encoder.Quality;

    // Create an EncoderParameters object.
    // An EncoderParameters object has an array of EncoderParameter
    // objects. In this case, there is only one
    // EncoderParameter object in the array.
    EncoderParameters myEncoderParameters = new EncoderParameters(1);

    EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, 
        50L);
    myEncoderParameters.Param[0] = myEncoderParameter;
    bmp1.Save(@"c:\TestPhotoQualityFifty.jpg", jgpEncoder, 
        myEncoderParameters);

    myEncoderParameter = new EncoderParameter(myEncoder, 100L);
    myEncoderParameters.Param[0] = myEncoderParameter;
    bmp1.Save(@"c:\TestPhotoQualityHundred.jpg", jgpEncoder, 
        myEncoderParameters);

    // Save the bitmap as a JPG file with zero quality level compression.
    myEncoderParameter = new EncoderParameter(myEncoder, 0L);
    myEncoderParameters.Param[0] = myEncoderParameter;
    bmp1.Save(@"c:\TestPhotoQualityZero.jpg", jgpEncoder, 
        myEncoderParameters);

}

验证此stackoverflow.com/questions/1484759/quality-of-a-saved-jpg-in-c-sharp

Answer 2

我建议你先读这个 -
How to: Set JPEG Compression Level
Turning off JPEG color downsampling for Bitmap.Save()

您可以将其保存到MemoryStream，然后从中加载新的位图的MemoryStream。

尝试这种方法：

// Get a bitmap.
Bitmap bmp1 = new Bitmap(@"c:\TestPhoto.jpg");
ImageCodecInfo jpgEncoder = GetEncoder(ImageFormat.Jpeg);

// Create an Encoder object based on the GUID
// for the Quality parameter category.
System.Drawing.Imaging.Encoder myEncoder =
    System.Drawing.Imaging.Encoder.Quality;

// Create an EncoderParameters object.
// An EncoderParameters object has an array of EncoderParameter
// objects. In this case, there is only one
// EncoderParameter object in the array.
EncoderParameters myEncoderParameters = new EncoderParameters(1);

EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, 50L);
myEncoderParameters.Param[0] = myEncoderParameter;
MemoryStream ms = new MemoryStream();
bmp1.Save(ms, jpgEncoder, myEncoderParameters); 
pictureBox.Image = Image.FromStream(ms);

.....

private ImageCodecInfo GetEncoder(ImageFormat format)
{

    ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();

    foreach (ImageCodecInfo codec in codecs)
    {
        if (codec.FormatID == format.Guid)
        {
            return codec;
        }
    }
    return null;
}

在标准Picturebox中仅显示50％质量的图像

2 个答案: