我正在编写一个需要打印高分辨率 .tiff 图像的程序。我遇到的问题是我无法打印高质量的 .tiff。由于 .tiff 的尺寸较大(例如 8700x7200),它不适合任何标准尺寸的纸张。我尝试增加 DPI,但这似乎没有任何效果。我能让 .tiff 适合页面的唯一方法是缩小它。但随后图像具有可怕的质量。 (我将其缩小以适合 11x17,但它的指示分辨率仅为 1100x1700)。我尝试更改打印机上的分辨率设置,尝试手动和以编程方式设置打印机质量/分辨率,但没有成功。基本上我希望能够将更多像素的 .tiff 放到 11x17 页面上,这样我就不必缩放太多。我认为增加打印 dpi 会增加 11x17 英寸的像素数量,但我看不出有什么效果。也许我做错了什么。任何帮助将不胜感激。谢谢。
下面的代码是我在调用 pd.Print() 时尝试立即执行的操作。
private void pd_PrintPage(object sender, PrintPageEventArgs ev)
{
//float x = ev.MarginBounds.Left;
//float y = ev.MarginBounds.Top;
try
{
//ResizeImage(@"H:\21RR-G0K-30140-0220-0002.tiff", @"H:\21RR-G0K-30140-0220-0002-new.tiff", 500, 900, false);
Image tempImage = Image.FromFile(@"H:\21RR-G0K-30140-0220-0002.tiff");
Bitmap bMap = new Bitmap(tempImage);
bMap.SetResolution(1200, 1200);
string l = "";
tempImage = bMap;
/*if (tempImage.Width > tempImage.Height) //if poster is longer then it is tall, rotate the image. Done to match standard printing aspect ratios
{
Bitmap tempBitmap = new Bitmap(tempImage); //Need to convert to Bitmap type to do rotation
RotateBicubic rotationFilter = new RotateBicubic(90, true);
tempImage = rotationFilter.Apply(tempBitmap);
}*/
float ImageAspectRatio = (float)tempImage.Height / (float)tempImage.Width;
float PageSizeAspectRatio = (float)_pSize.Height / (float)_pSize.Width; //_pSize is the selected printing sheet size
if (ImageAspectRatio < 1 && PageSizeAspectRatio > 1) //Need to rotate Image. Can't attempt to rotate tempImage due to size. Scale then rotate.
{
double x_scale = (double)_pSize.Width / (double)tempImage.Height;
double y_scale = (double)_pSize.Height / (double)tempImage.Width;
int percent = 0;
if (y_scale < x_scale)
{
percent = Convert.ToInt32(y_scale * 100);
}
else
{
percent = Convert.ToInt32(x_scale * 100);
}
Image myImage = ImageManipulation.ScaleByPercent(tempImage, percent); //I know this line is the problem, but I can't fit the image on the page without massive scaling due to the page reolution restraints
Bitmap tempMap = new Bitmap(myImage);
tempMap.SetResolution(1200, 1200);
RotateBicubic rotateBC = new RotateBicubic(90);
Image finalImage = rotateBC.Apply(tempMap); //rotate the image 90 degrees using bicubic interpolation. This isn't what's killing the quality as the quality is no better with this disabled
ev.Graphics.DrawImage(finalImage, 0, 0);
}
else if (ImageAspectRatio >= 1 && PageSizeAspectRatio >= 1) //No Need for rotation
{
double x_scale = (double)_pSize.Width / (double)tempImage.Width;
double y_scale = (double)_pSize.Height / (double)tempImage.Height;
int percent = 0;
if (y_scale < x_scale)
{
percent = Convert.ToInt32(y_scale * 100);
}
else
{
percent = Convert.ToInt32(x_scale * 100);
}
Image myImage = ImageManipulation.ScaleByPercent(tempImage, percent);
ev.Graphics.DrawImage(myImage, 0, 0);
}
else
{
}
}
catch(Exception ex)
{
string breakingpoint = "";
}
}
最佳答案
您要查找的术语是“重采样”。
使用设备坐标系或 GDI+ HIENGLISH 单位缩放图像可能也是最好的(我相信这是在打印设备上下文中使用的。)
使用 DrawImage 命令,您将从 GDI+ 获得的最佳效果是 HighQualityBicubic Resampling。
Private Sub pd_PrintPage(ByVal sender As System.Object, ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles pd.PrintPage
Dim img As Image = Image.FromFile("SAMPLE.TIF")
Dim imageWidth As Integer = CInt((img.Width / img.HorizontalResolution) * 100)
Dim imageHeight As Integer = CInt((img.Height / img.VerticalResolution) * 100)
If imageWidth > e.PageBounds.Width Then
Dim ratio As Double = imageWidth / imageHeight
imageWidth = e.PageBounds.Width
If ratio < 1 Then
imageHeight = CInt(imageWidth * ratio)
Else
imageHeight = CInt(imageWidth / ratio)
End If
End If
If imageHeight > e.PageBounds.Height Then
Dim ratio As Double = imageHeight / imageWidth
imageHeight = e.PageBounds.Height
If ratio < 1 Then
imageWidth = CInt(imageHeight * ratio)
Else
imageWidth = CInt(imageHeight / ratio)
End If
End If
e.Graphics.InterpolationMode = Drawing2D.InterpolationMode.HighQualityBicubic
e.Graphics.DrawImage(img, 0, 0, imageWidth, imageHeight)
End Sub
关于c# - 提高图像的打印质量,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/1079222/