Question

我使用Graphics.DrawImage(DrawText())将DrawText用于Image。

问题是：我只绘制了三个文本，但原始图像大小为：226kb，当Save（）~3.45mb时输出图像。它太大了。

图片尺寸：2732 * 3200。

我只循环列表textFileSplit，此列表只有三个项目。

这是我保存图片的全部代码：

foreach (string text in lstTextFromFile)
{
    count++;
    if (text == "") continue;
    Graphics gra = Graphics.FromImage(img);
    string st = lstImgAdded.Items[k].Text;
    Bitmap bmp = new Bitmap(@"" + st);
    bmp = (Bitmap)ResizePanel(bmp, panel2);
    panel2.BackgroundImage = bmp;
    Graphics gbmp = Graphics.FromImage(bmp);
    string[] textFileSplit = text.Split('-');
    for (int u = 0; u < textFileSplit.Count(); u++)
    {
        myColorLabel = activeLabels[u+1].ForeColor;
        gbmp.DrawImage(
        DrawText(textFileSplit[u], fontType, myColorLabel,
            Color.Transparent),
        Point.Round(StretchImageSize(new Point(activeLabels[u+1].Location.X, activeLabels[u+1].Location.Y), panel2)));
    }
    gra.Dispose();
    Guid id = Guid.NewGuid();
    ScaleImage(bmp, witdhImg, heightImg)
        .Save(linkLocation + "\\" + id + "." + imgType,
            ImageFormat.Png);
}

在课程ScaleImage()中，我试图像原始图片一样保留尺寸：

public Image ScaleImage(Image image, int maxWidth, int maxHeight)
{
    var ratioX = (double)maxWidth / image.Width;
    var ratioY = (double)maxHeight / image.Height;
    var ratio = Math.Min(ratioX, ratioY);
    var ratio2 = Math.Max(ratioX, ratioY);

    var newWidth = (int)(image.Width * ratio);
    var newHeight = (int)(image.Height * ratio2);

    var newImage = new Bitmap(newWidth, newHeight);
    Graphics.FromImage(newImage).DrawImage(image, 0, 0, newWidth, newHeight);
    return newImage;
}

Answer 1

确保在缩放功能中设置分辨率和质量：

    public Image ScaleImage(Image image, int maxWidth, int maxHeight)
    {
        var ratioX = (double)maxWidth / image.Width;
        var ratioY = (double)maxHeight / image.Height;
        var ratio = Math.Min(ratioX, ratioY);
        var ratio2 = Math.Max(ratioX, ratioY);

        var newWidth = (int)(image.Width * ratio);
        var newHeight = (int)(image.Height * ratio2);

        var newImage = var newImage = new Bitmap(newWidth, newHeight, image.PixelFormat);
        newImage.SetResolution(image.HorizontalResolution, image.VerticalResolution);

        Graphics grPhoto = Graphics.FromImage(newImage);
        grPhoto.InterpolationMode = InterpolationMode.High;

        grPhoto.DrawImage(image, 0, 0, newWidth, newHeight);

        grPhoto.Dispose();
        return newImage;           
    }

以低质量应用EncoderParameters：

   ImageCodecInfo pngEncoder = ImageCodecInfo.GetImageDecoders().Where(k=> k.FormatID == ImageFormat.Png.Guid).First();
   EncoderParameters encoderParameters;
   encoderParameters = new EncoderParameters(1);
   encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality,  60L);
   ScaleImage(bmp, witdhImg, heightImg)
    .Save(linkLocation + "\\" + id + "." + imgType, pngEncoder ,encoderParameters);

如何减少C＃中的图像大小？

1 个答案: