代码打开图像使其流通，但是我想要的是使他的角落尽可能平滑而没有非常粗糙的边缘
img具有60x60注意：忽略蓝色边框
尝试切换平滑模式但没有成功
我到目前为止在该项目中做了什么
private void Recorte_Click(object sender, EventArgs e)
{
OpenFileDialog open = new OpenFileDialog();
// Filter for image files
open.Filter = "Image Files(*.jpg; *.jpeg; *.gif; *.bmp; *.png)|*.jpg; *.jpeg; *.gif; *.bmp; *.png";
if (open.ShowDialog() == DialogResult.OK)
{
// display image in picture box
PointF p = new PointF(1, 1);
Bitmap org = new Bitmap(open.FileName);
Image srcImage = Bitmap.FromFile(open.FileName);
// Resize image in 60x60
Image resized = ResizeImage(srcImage, new Size(60, 60), false);
MemoryStream memStream = new MemoryStream();
// Crop in round shape
Image cropped = CropToCircle(resized,Color.Transparent);
cropped.Save(@"..\..\Cortada.png", System.Drawing.Imaging.ImageFormat.Png);
pictureBox1.Image = cropped;
}
}
public static Image CropToCircle(Image srcImage, Color backGround)
{
Image dstImage = new Bitmap(srcImage.Width, srcImage.Height, srcImage.PixelFormat);
Graphics g = Graphics.FromImage(dstImage);
using (Brush br = new SolidBrush(backGround))
{
g.FillRectangle(br, 0, 0, dstImage.Width, dstImage.Height);
}
float radius = 25;
PointF center = new Point(60, 60);
GraphicsPath path = new GraphicsPath();
path.AddEllipse(7, 7, radius * 2, radius * 2);
g.SetClip(path);
g.SmoothingMode = SmoothingMode.AntiAlias;
g.InterpolationMode = InterpolationMode.HighQualityBilinear;
g.SmoothingMode = SmoothingMode.AntiAlias;
g.DrawImage(srcImage, 0, 0);
return dstImage;
}
public static Image ResizeImage(Image image, Size size, bool preserveAspectRatio = true)
{
int newWidth;
int newHeight;
if (preserveAspectRatio)
{
int originalWidth = image.Width;
int originalHeight = image.Height;
float percentWidth = (float)size.Width / (float)originalWidth;
float percentHeight = (float)size.Height / (float)originalHeight;
float percent = percentHeight < percentWidth ? percentHeight : percentWidth;
newWidth = (int)(originalWidth * percent);
newHeight = (int)(originalHeight * percent);
}
else
{
newWidth = size.Width;
newHeight = size.Height;
}
Image newImage = new Bitmap(newWidth, newHeight);
using (Graphics graphicsHandle = Graphics.FromImage(newImage))
{
graphicsHandle.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphicsHandle.DrawImage(image, 0, 0, newWidth, newHeight);
}
return newImage;
}
要使此功能按预期工作，需要进行一些更改：
处置创建的一次性对象非常重要，尤其是在处理图形对象时，但是您需要处置所有创建的具有Dispose()方法的对象（其中包括OpenFileDialog对象）。
请勿以这种形式使用路径：@"..\..\Image.png"：将可执行文件移动到其他位置时，该路径将不存在（否则将无法访问，或者根本就是错误的）。始终使用Path.Combine()（如下所示）构建完整路径。此处的示例将Image保存在可执行路径的CroppedImages子文件夹中。不过，该主题的内容非常广泛（例如，可能不允许您将数据存储在可执行路径中，因此您可能需要在User AppData文件夹中使用专用路径）。
不使用Image.Fromfile()：如果出于某些原因必须使用，请始终使用允许保留嵌入的色彩管理信息的重载（string, bool）。由于可以避免这种情况，请使用此处显示的方法，使用File.ReadAllBytes()和MemoryStream（或FileStream块中的using）。
Graphics.SetClip()不允许抗锯齿，因为构建区域（至少不是直接构建）。在这里，我使用的是TextureBrush，它是从位图（您调整大小后的位图）生成的特殊笔刷，然后将其用于填充调整大小后的图像crops的椭圆。
所有计算都需要重新访问，看看我在这里发布的内容。
private void Recorte_Click(object sender, EventArgs e)
{
using (var ofd = new OpenFileDialog()) {
ofd.Filter = "Image Files (*.jpg; *.jpeg; *.gif; *.bmp; *.png)|*.jpg; *.jpeg; *.gif; *.bmp; *.png";
ofd.RestoreDirectory = true;
if (ofd.ShowDialog() != DialogResult.OK) return;
Image croppedImage = null;
using (var sourceImage = Image.FromStream(new MemoryStream(File.ReadAllBytes(ofd.FileName))))
using (var resizedImage = ResizeImage(sourceImage, new Size(100, 300), false)) {
croppedImage = CropToCircle(resizedImage, Color.Transparent, Color.Turquoise);
pictureBox1.Image?.Dispose();
pictureBox1.Image = croppedImage;
string destinationPath = Path.Combine(Application.StartupPath, @"CroppedImages\Cortada.png");
croppedImage.Save(destinationPath, ImageFormat.Png);
}
}
}
CropToCircle方法被重写，并且我添加了允许指定笔颜色的重载。然后将使用钢笔在裁剪的椭圆区域周围绘制边框。
public static Image CropToCircle(Image srcImage, Color backColor)
{
return CropToCircle(srcImage, backColor, Color.Transparent);
}
public static Image CropToCircle(Image srcImage, Color backColor, Color penColor)
{
var rect = new Rectangle(1, 1, srcImage.Width - 1, srcImage.Height - 1);
var cropped = new Bitmap(srcImage.Width, srcImage.Height, PixelFormat.Format32bppArgb);
using (var tBrush = new TextureBrush(srcImage))
using (var pen = new Pen(penColor, 2))
using (var g = Graphics.FromImage(cropped)) {
g.SmoothingMode = SmoothingMode.AntiAlias;
if (backColor != Color.Transparent) g.Clear(backColor);
g.FillEllipse(tBrush, rect);
if (penColor != Color.Transparent) {
rect.Inflate(-2, -2);
g.DrawEllipse(pen, rect);
}
return cropped;
}
}
ResizeImage方法得到简化。
PixelOffsetMode.Half。 The notes here explain why。 public static Image ResizeImage(Image image, Size newSize, bool preserveAspectRatio = true)
{
float scale = Math.Max(newSize.Width, newSize.Height) / (float)Math.Max(image.Width, image.Height);
Size imageSize = preserveAspectRatio
? Size.Round(new SizeF(image.Width * scale, image.Height * scale))
: newSize;
var resizedImage = new Bitmap(imageSize.Width, imageSize.Height);
using (var g = Graphics.FromImage(resizedImage)) {
g.PixelOffsetMode = PixelOffsetMode.Half;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(image, 0, 0, imageSize.Width, imageSize.Height);
}
return resizedImage;
}