我正在开展涉及裁剪图像的winforms项目。我的目标是使用固定大小的可拖动图片框控件,允许用户选择他们想要保留的区域。
我的问题是当我裁剪图像时;它“工作”,但裁剪区域偏移了一点。这是我得到的结果:
为了澄清,我不是在谈论缩放,这是每个设计。请注意,橙色框主要关注风暴的眼睛,但裁剪的图像不是。
这是我的裁剪操作代码:
private void tsbRecortar_Click(object sender, EventArgs e)
{
Rectangle recorte = new Rectangle(pbxSeleccion.Location.X, pbxSeleccion.Location.Y, pbxSeleccion.Width, pbxSeleccion.Height);
foto = recortarImagen(foto, recorte);
pbxImagen.Image = foto;
}
private Image recortarImagen(Image imagen, Rectangle recuadro)
{
try
{
Bitmap bitmap = new Bitmap(imagen);
Bitmap cropedBitmap = bitmap.Clone(recuadro, bitmap.PixelFormat);
return (Image)(cropedBitmap);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Error");
return null;
}
}
pbxSeleccion 是可拖动的橙色矩形;它的父级是 pbxImage (我在表单加载时重新为它父。)
正如你所看到的,我正在使用 pbxSeleccion 的坐标来定义裁剪区域的起点,但是没有按预期工作......有时,我甚至得到一个“Out”记忆“例外。
我认为这与图像在父图片框中的加载方式有关,关于如何在“引擎盖下”处理边距,但我没有尝试修复它...只是改变了偏移的大小。 / p>
搜索网络和SO帮助了我很多,但对于这个特殊问题,我似乎无法找到答案...请随意指出我的代码改进,我没有编码很久,我是C#和.NET的新手
非常感谢任何帮助。干杯!
答案 0 :(得分:1)
假设您的原始图片显示在PictureBox
中。您传递到橙色裁剪窗口的错误位置。以下是为您更正的代码:
private void tsbRecortar_Click(object sender, EventArgs e){
Point p = yourPictureBox.PointToClient(pbxSelection.PointToScreen(Point.Empty));
Rectangle recorte = new Rectangle(p.X, p.Y, pbxSeleccion.Width, pbxSeleccion.Height);
foto = recortarImagen(foto, recorte);
pbxImagen.Image = foto;
}
我在这里使用PointToClient
和PointToScreen
因为我认为这是最好的方法。然后,您可以安全地更改pictureBox
的容器,而无需修改代码。如果您使用如下代码,那么当您想将pictureBox
放在另一个容器中时,它就不够动态了:
Rectangle recorte = new Rectangle(pbxSeleccion.X + yourPictureBox.Left,
pbxSeleccion.Y + yourPictureBox.Top,
pbxSeleccion.Width, pbxSeleccion.Height);
注意:您也可以像这样使用RectangleToClient
和RectangleToScreen
:
private void tsbRecortar_Click(object sender, EventArgs e){
Rectangle recorte = yourPictureBox.RectangleToClient(pbxSeleccion.RectangleToScreen(pbxSeleccion.ClientRectangle));
foto = recortarImagen(foto, recorte);
pbxImagen.Image = foto;
}
答案 1 :(得分:1)
尝试使用此代码在图片框中裁剪图像
public static Image Fit2PictureBox(this Image image, PictureBox picBox)
{
Bitmap bmp = null;
Graphics g;
// Scale:
double scaleY = (double)image.Width / picBox.Width;
double scaleX = (double)image.Height / picBox.Height;
double scale = scaleY < scaleX ? scaleX : scaleY;
// Create new bitmap:
bmp = new Bitmap(
(int)((double)image.Width / scale),
(int)((double)image.Height / scale));
// Set resolution of the new image:
bmp.SetResolution(
image.HorizontalResolution,
image.VerticalResolution);
// Create graphics:
g = Graphics.FromImage(bmp);
// Set interpolation mode:
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
// Draw the new image:
g.DrawImage(
image,
new Rectangle( // Ziel
0, 0,
bmp.Width, bmp.Height),
new Rectangle( // Quelle
0, 0,
image.Width, image.Height),
GraphicsUnit.Pixel);
// Release the resources of the graphics:
g.Dispose();
// Release the resources of the origin image:
image.Dispose();
return bmp;
}
public static Image Crop(this Image image, Rectangle selection)
{
Bitmap bmp = image as Bitmap;
// Check if it is a bitmap:
if (bmp == null)
throw new ArgumentException("Kein gültiges Bild (Bitmap)");
// Crop the image:
Bitmap cropBmp = bmp.Clone(selection, bmp.PixelFormat);
// Release the resources:
image.Dispose();
return cropBmp;
}
在PictureBox上为鼠标事件编写以下代码
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
_selecting = true;
_selection = new Rectangle(new Point(e.X, e.Y), new Size());
}
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left && _selecting)
{
// Create cropped image:
try
{
Image img = pictureBox1.Image.Crop(_selection);
// Fit image to the picturebox:
pictureBox1.Image = img.Fit2PictureBox(pictureBox1);
}
catch { }
_selecting = false;
}
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
// Update the actual size of the selection:
if (_selecting)
{
_selection.Width = e.X - _selection.X;
_selection.Height = e.Y - _selection.Y;
// Redraw the picturebox:
pictureBox1.Refresh();
}
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
if (_selecting)
{
// Draw a rectangle displaying the current selection
Pen pen = Pens.LightSkyBlue;
e.Graphics.DrawRectangle(pen, _selection);
}
}
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