在 imagebox 控件中裁剪图像并保存
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【中文标题】在 imagebox 控件中裁剪图像并保存【英文标题】：Crop an image in imagebox control and save it 【发布时间】：2013-07-08 07:16:31 【问题描述】：我正在做一个程序来设计卡片并实时显示图像。我已经完成了那部分，它工作得很好。现在我需要裁剪图像并保存为它的保存方式，在顶部和底部有 2 个白条。这是我现在用来保存的代码。
private void SaveCardbtn_Click(object sender, EventArgs e)
//Open the saveFileDialog
if (saveWork.ShowDialog() == System.Windows.Forms.DialogResult.OK)
CardImg.Image.Save(saveWork.FileName, ImageFormat.Jpeg);
谢谢。
【问题讨论】：
问题是什么？ 问题是如何裁剪图像然后保存 【参考方案1】：我已经在 asp .net 论坛上发布了这个答案。 请试试这个 -
以下裁剪函数将接受 4 个参数：
Width：这将是裁剪图像的宽度。
Height：这将是裁剪图像的高度。
Source Image File Path：这将是源图像文件的完整路径。
Save Cropped Image File Path：这将是保存裁剪图像文件的完整路径。
public static void CropImage(int Width, int Height, string sourceFilePath, string saveFilePath)
// variable for percentage resize
float percentageResize = 0;
float percentageResizeW = 0;
float percentageResizeH = 0;
// variables for the dimension of source and cropped image
int sourceX = 0;
int sourceY = 0;
int destX = 0;
int destY = 0;
// Create a bitmap object file from source file
Bitmap sourceImage = new Bitmap(sourceFilePath);
// Set the source dimension to the variables
int sourceWidth = sourceImage.Width;
int sourceHeight = sourceImage.Height;
// Calculate the percentage resize
percentageResizeW = ((float)Width / (float)sourceWidth);
percentageResizeH = ((float)Height / (float)sourceHeight);
// Checking the resize percentage
if (percentageResizeH < percentageResizeW)
percentageResize = percentageResizeW;
destY = System.Convert.ToInt16((Height - (sourceHeight * percentageResize)) / 2);
else
percentageResize = percentageResizeH;
destX = System.Convert.ToInt16((Width - (sourceWidth * percentageResize)) / 2);
// Set the new cropped percentage image
int destWidth = (int)Math.Round(sourceWidth * percentageResize);
int destHeight = (int)Math.Round(sourceHeight * percentageResize);
// Create the image object
using (Bitmap objBitmap = new Bitmap(Width, Height))
objBitmap.SetResolution(sourceImage.HorizontalResolution, sourceImage.VerticalResolution);
using (Graphics objGraphics = Graphics.FromImage(objBitmap))
// Set the graphic format for better result cropping
objGraphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
objGraphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
objGraphics.DrawImage(sourceImage, new Rectangle(destX, destY, destWidth, destHeight), new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight), GraphicsUnit.Pixel);
// Save the file path, note we use png format to support png file
objBitmap.Save(saveFilePath, ImageFormat.Png);
使用以下代码调用上述CropImage方法：
CropImage(100, 100, "c://destinationimage.jpg", "c://newcroppedimage.jpg");
希望对您有所帮助！
【讨论】：
这很好，谢谢，只是希望我可以让它与 imagebox 一起工作【参考方案2】：我使用此代码进行图像裁剪。请注意 pbOriginalImage 是你的图片框，里面有图片。
private void pbOriginalImage_MouseDown(object sender, MouseEventArgs e)
try
// Starting point of the selection:
if (e.Button == MouseButtons.Left)
_selecting = true;
_selection = new Rectangle(new Point(e.X, e.Y), new Size());
catch (Exception ex)
ApplicationExceptions.HandleAppExc(ex);
private void pbOriginalImage_MouseMove(object sender, MouseEventArgs e)
try
// Update the actual size of the selection:
if (_selecting)
_selection.Width = e.X - _selection.X;
_selection.Height = e.Y - _selection.Y;
// Redraw the picturebox:
pbOriginalImage.Refresh();
catch (Exception ex)
ApplicationExceptions.HandleAppExc(ex);
private void pbOriginalImage_MouseUp(object sender, MouseEventArgs e)
try
if (pbOriginalImage.Image == null)
return;
if (e.Button == MouseButtons.Left && _selecting)
// check selection rectangle has non-zero Height and Width
if (!ValidateSelection(_selection))
_selecting = false;
return;
// Check that selection rectangle does extend outside of image boundaries
ValidateRectangleSize();
// Create cropped image:
Image tempImage = pbOriginalImage.Image.Clone() as Image;
Image img = tempImage.Crop(_selection);
// Fit image to the picturebox:
profileImage.Image = img.Fit2PictureBox(profileImage);
_selecting = false;
catch (Exception ex)
ApplicationExceptions.HandleAppExc(ex);
private void pbOriginalImage_Paint(object sender, PaintEventArgs e)
try
if (_selecting)
// Draw a rectangle displaying the current selection
Pen pen = Pens.GreenYellow;
e.Graphics.DrawRectangle(pen, _selection);
catch (Exception ex)
ApplicationExceptions.HandleAppExc(ex);
throw;
private void commandBrowse_Click(object sender, EventArgs e)
try
using (OpenFileDialog dlg = new OpenFileDialog())
dlg.Filter = "JPG Files (*.jpg)|*.jpg|JPEG Files (*.jpeg)|*.jpeg|bmp Files (*.bmp)|*.bmp|PNG Files (*.png)|*.png|GIF Files (*.gif)|*.gif";
if (dlg.ShowDialog() == DialogResult.OK)
FileInfo file = new FileInfo(dlg.FileName);
if (file.Length == 0)
MessageBoxEx.Show("Invalid image. Please select valid image.", Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
else if (file.Length > 2097152)
MessageBoxEx.Show("Image size cannot exceed 2MB.", Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
textProfileImagePath.Text = dlg.FileName;
pbOriginalImage.Image = Image.FromFile(dlg.FileName).Fit2PictureBox(pbOriginalImage);
profileImage.Image = Image.FromFile(dlg.FileName).Fit2PictureBox(profileImage);
catch (Exception ex)
if (ex.Message.Contains("Out of memory"))
MessageBoxEx.Show("Invalid image. Please select valid image.", Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Information);
else
ApplicationExceptions.HandleAppExc(ex);
// Check that selection rectangle does extend outside of image boundaries
private void ValidateRectangleSize()
Size imgSize = this.pbOriginalImage.Image.Size;
int selectionWidth;
int selectionHeight;
// check width
if (_selection.X < 0)
_selection.X = 0;
selectionWidth = _selection.Width + _selection.X;
if (selectionWidth > imgSize.Width)
_selection.Width = imgSize.Width - _selection.X - 1;
// check height
if (_selection.Y < 0)
_selection.Y = 0;
selectionHeight = _selection.Height + _selection.Y;
if (selectionHeight > imgSize.Height)
_selection.Height = imgSize.Height - _selection.Y - 1;
// check selection rectangle has non-zero Height and Width
private bool ValidateSelection(Rectangle selection)
// routine to validate the selection
if (selection.Width <= 0 || selection.Height <= 0)
// if you get here a good rectangle was not created
return false;
else
return true;
这是我使用的扩展类。
public static class ImageExtension
/// <summary>
/// Crops an image according to a selection rectangel
/// </summary>
/// <param name="image">
/// the image to be cropped
/// </param>
/// <param name="selection">
/// the selection
/// </param>
/// <returns>
/// cropped image
/// </returns>
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("Not a valid image (Bitmap)");
// Crop the image:
Bitmap cropBmp = bmp.Clone(selection, bmp.PixelFormat);
// Release the resources:
image.Dispose();
return cropBmp;
//---------------------------------------------------------------------
/// <summary>
/// Fits an image to the size of a picturebox
/// </summary>
/// <param name="image">
/// image to be fit
/// </param>
/// <param name="picBox">
/// picturebox in that the image should fit
/// </param>
/// <returns>
/// fitted image
/// </returns>
/// <remarks>
/// Although the picturebox has the SizeMode-property that offers
/// the same functionality an OutOfMemory-Exception is thrown
/// when assigning images to a picturebox several times.
///
/// AFAIK the SizeMode is designed for assigning an image to
/// picturebox only once.
/// </remarks>
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;
【讨论】：
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