c# 在保持纵横比的同时将图像调整为不同的大小
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【中文标题】c# 在保持纵横比的同时将图像调整为不同的大小【英文标题】：c# Image resizing to different size while preserving aspect ratio 【发布时间】：2010-12-28 18:36:11 【问题描述】：我正在尝试调整图像的大小，同时保留原始图像的宽高比，这样新图像就不会被压扁。
例如：
将 150*100 的图像转换为 150*150 的图像。 额外的 50 像素高度需要用白色背景色填充。
这是我正在使用的当前代码。
它适用于调整大小，但更改原始图像的纵横比会挤压新图像。
private void resizeImage(string path, string originalFilename,
int width, int height)
Image image = Image.FromFile(path + originalFilename);
System.Drawing.Image thumbnail = new Bitmap(width, height);
System.Drawing.Graphics graphic =
System.Drawing.Graphics.FromImage(thumbnail);
graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphic.SmoothingMode = SmoothingMode.HighQuality;
graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
graphic.CompositingQuality = CompositingQuality.HighQuality;
graphic.DrawImage(image, 0, 0, width, height);
System.Drawing.Imaging.ImageCodecInfo[] info =
ImageCodecInfo.GetImageEncoders();
EncoderParameters encoderParameters;
encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality,
100L);
thumbnail.Save(path + width + "." + originalFilename, info[1],
encoderParameters);
编辑：我想要填充而不是裁剪图像
【问题讨论】：
【参考方案1】：应该这样做。
private void resizeImage(string path, string originalFilename,
/* note changed names */
int canvasWidth, int canvasHeight,
/* new */
int originalWidth, int originalHeight)
Image image = Image.FromFile(path + originalFilename);
System.Drawing.Image thumbnail =
new Bitmap(canvasWidth, canvasHeight); // changed parm names
System.Drawing.Graphics graphic =
System.Drawing.Graphics.FromImage(thumbnail);
graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphic.SmoothingMode = SmoothingMode.HighQuality;
graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
graphic.CompositingQuality = CompositingQuality.HighQuality;
/* ------------------ new code --------------- */
// Figure out the ratio
double ratioX = (double) canvasWidth / (double) originalWidth;
double ratioY = (double) canvasHeight / (double) originalHeight;
// use whichever multiplier is smaller
double ratio = ratioX < ratioY ? ratioX : ratioY;
// now we can get the new height and width
int newHeight = Convert.ToInt32(originalHeight * ratio);
int newWidth = Convert.ToInt32(originalWidth * ratio);
// Now calculate the X,Y position of the upper-left corner
// (one of these will always be zero)
int posX = Convert.ToInt32((canvasWidth - (originalWidth * ratio)) / 2);
int posY = Convert.ToInt32((canvasHeight - (originalHeight * ratio)) / 2);
graphic.Clear(Color.White); // white padding
graphic.DrawImage(image, posX, posY, newWidth, newHeight);
/* ------------- end new code ---------------- */
System.Drawing.Imaging.ImageCodecInfo[] info =
ImageCodecInfo.GetImageEncoders();
EncoderParameters encoderParameters;
encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality,
100L);
thumbnail.Save(path + newWidth + "." + originalFilename, info[1],
encoderParameters);
编辑添加：
那些想要改进这个代码的人应该把它放在 cmets 中，或者一个新的答案。不要直接编辑此代码。
【讨论】：
只是想知道参数 originalWidth 和 originalHeight，当您可以从图像中获取这些信息时，为什么需要它们？ （在我获得评论权限之前，我确实编辑过你的代码，对此我深表歉意） @mendel - 是的，这也可以。但是在最初的问题中他已经知道了高度和宽度，那为什么还要重新计算呢？ 我在一张 1024*768 的图像上尝试过这个转换为 500*500 的图像 - 图像失真了。我正在寻找类似 wordpress CMS 的算法，其中图像在缩小尺寸时不会失真（但是从侧面进行了一些裁剪）。 @yogihosting 发布有关您的问题的问题，包括您的代码，甚至可能是指向测试图像的链接。这对其他人有用，所以我们需要看看对你有什么不同。 @egrunin 我建议在加载原始图像时使用Path.Combine(path, originalFileName)。最后保存缩略图时相同。【参考方案2】：
通过学习this CodeProject Article，我发现了如何调整图像大小和填充图像。
static Image FixedSize(Image imgPhoto, int Width, int Height)
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int sourceX = 0;
int sourceY = 0;
int destX = 0;
int destY = 0;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)Width / (float)sourceWidth);
nPercentH = ((float)Height / (float)sourceHeight);
if (nPercentH < nPercentW)
nPercent = nPercentH;
destX = System.Convert.ToInt16((Width -
(sourceWidth * nPercent)) / 2);
else
nPercent = nPercentW;
destY = System.Convert.ToInt16((Height -
(sourceHeight * nPercent)) / 2);
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(Width, Height,
PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.Red);
grPhoto.InterpolationMode =
InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto,
new Rectangle(destX, destY, destWidth, destHeight),
new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
return bmPhoto;
【讨论】：
@bobek 只关闭原图 imgPhoto.Dispose(); 不错的代码！如果对 Graphics.FromImage(bmPhoto); 使用“使用模式”，则更清洁。并且 sourceX 和 sourceY 变量被丢弃并在 'new Rectangle(0, 0, sourceWidth, sourceHeight)' 中设置为 0 字面量 正是我需要的 ;) 当您需要传递图像参数而不是实际路径时特别有用。 代码不错，但我建议使用 Color.White 而不是 Color.Red【参考方案3】：我使用以下方法来计算所需的图像尺寸：
using System.Drawing;
public static Size ResizeKeepAspect(this Size src, int maxWidth, int maxHeight, bool enlarge = false)
maxWidth = enlarge ? maxWidth : Math.Min(maxWidth, src.Width);
maxHeight = enlarge ? maxHeight : Math.Min(maxHeight, src.Height);
decimal rnd = Math.Min(maxWidth / (decimal)src.Width, maxHeight / (decimal)src.Height);
return new Size((int)Math.Round(src.Width * rnd), (int)Math.Round(src.Height * rnd));
这将纵横比和尺寸的问题放在一个单独的方法中。
【讨论】：
如果我想做一个“填充”怎么办？enlarge 是这样做的吗？
@MathiasLykkegaardLorenzen 通常你只会缩小图像，因为放大意味着质量损失 - 所以如果你想这样做，我添加了这个可选参数【参考方案4】：
为了得到更快的结果，获取大小的函数可以在resultSize中找到：
Size original = new Size(640, 480);
int maxSize = 100;
float percent = (new List<float> (float)maxSize / (float)original.Width , (float)maxSize / (float)original.Height ).Min();
Size resultSize = new Size((int)Math.Floor(original.Width * percent), (int)Math.Floor(original.Height * percent));
使用Linq 最小化变量和重新计算，以及不必要的if/else 语句
【讨论】：
这是一个绝妙的解决方案！非常简洁和小巧。我将它的修改版本与 System.Web.Helpers.WebImage 一起使用，以即时按比例调整图像大小。干得好！If/else 会比分配列表更好，Math.Min 也是一种选择【参考方案5】：
只是将其概括为纵横比和大小，图像的东西可以在这个函数之外完成
public static d.RectangleF ScaleRect(d.RectangleF dest, d.RectangleF src,
bool keepWidth, bool keepHeight)
d.RectangleF destRect = new d.RectangleF();
float sourceAspect = src.Width / src.Height;
float destAspect = dest.Width / dest.Height;
if (sourceAspect > destAspect)
// wider than high keep the width and scale the height
destRect.Width = dest.Width;
destRect.Height = dest.Width / sourceAspect;
if (keepHeight)
float resizePerc = dest.Height / destRect.Height;
destRect.Width = dest.Width * resizePerc;
destRect.Height = dest.Height;
else
// higher than wide – keep the height and scale the width
destRect.Height = dest.Height;
destRect.Width = dest.Height * sourceAspect;
if (keepWidth)
float resizePerc = dest.Width / destRect.Width;
destRect.Width = dest.Width;
destRect.Height = dest.Height * resizePerc;
return destRect;
【讨论】：
分离这个问题是个好主意。您可以使用SizeF 代替RectangleF。【参考方案6】：
我也将在这里添加我的代码。此代码将允许您调整图像的大小，无论是否强制执行纵横比或使用填充调整大小。这是 egrunin 代码的修改版本。
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
namespace ConsoleApplication1
public class Program
public static void Main(string[] args)
var path = Directory.GetParent(Directory.GetCurrentDirectory()).Parent.FullName;
ResizeImage(path, "large.jpg", path, "new.jpg", 100, 100, true, true);
/// <summary>Resizes an image to a new width and height.</summary>
/// <param name="originalPath">The folder which holds the original image.</param>
/// <param name="originalFileName">The file name of the original image.</param>
/// <param name="newPath">The folder which will hold the resized image.</param>
/// <param name="newFileName">The file name of the resized image.</param>
/// <param name="maximumWidth">When resizing the image, this is the maximum width to resize the image to.</param>
/// <param name="maximumHeight">When resizing the image, this is the maximum height to resize the image to.</param>
/// <param name="enforceRatio">Indicates whether to keep the width/height ratio aspect or not. If set to false, images with an unequal width and height will be distorted and padding is disregarded. If set to true, the width/height ratio aspect is maintained and distortion does not occur.</param>
/// <param name="addPadding">Indicates whether fill the smaller dimension of the image with a white background. If set to true, the white padding fills the smaller dimension until it reach the specified max width or height. This is used for maintaining a 1:1 ratio if the max width and height are the same.</param>
private static void ResizeImage(string originalPath, string originalFileName, string newPath, string newFileName, int maximumWidth, int maximumHeight, bool enforceRatio, bool addPadding)
var image = Image.FromFile(originalPath + "\\" + originalFileName);
var imageEncoders = ImageCodecInfo.GetImageEncoders();
EncoderParameters encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality, 100L);
var canvasWidth = maximumWidth;
var canvasHeight = maximumHeight;
var newImageWidth = maximumWidth;
var newImageHeight = maximumHeight;
var xPosition = 0;
var yPosition = 0;
if (enforceRatio)
var ratioX = maximumWidth / (double)image.Width;
var ratioY = maximumHeight / (double)image.Height;
var ratio = ratioX < ratioY ? ratioX : ratioY;
newImageHeight = (int)(image.Height * ratio);
newImageWidth = (int)(image.Width * ratio);
if (addPadding)
xPosition = (int)((maximumWidth - (image.Width * ratio)) / 2);
yPosition = (int)((maximumHeight - (image.Height * ratio)) / 2);
else
canvasWidth = newImageWidth;
canvasHeight = newImageHeight;
var thumbnail = new Bitmap(canvasWidth, canvasHeight);
var graphic = Graphics.FromImage(thumbnail);
if (enforceRatio && addPadding)
graphic.Clear(Color.White);
graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphic.SmoothingMode = SmoothingMode.HighQuality;
graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
graphic.CompositingQuality = CompositingQuality.HighQuality;
graphic.DrawImage(image, xPosition, yPosition, newImageWidth, newImageHeight);
thumbnail.Save(newPath + "\\" + newFileName, imageEncoders[1], encoderParameters);
【讨论】：
记得添加对 System.Drawing DLL 的引用。 此代码将图像旋转 90 度 - 缩略图与原始图像相比旋转 - 为什么？【参考方案7】：这是一个不太具体的扩展方法，它适用于 Image 而不是为您进行加载和保存。它还允许您在使用 NearestNeighbour 插值时指定插值方法并正确渲染边缘。
图像将在您指定的区域范围内呈现，因此您始终知道输出的宽度和高度。例如：
namespace YourApp
#region Namespaces
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
#endregion
/// <summary>Generic helper functions related to graphics.</summary>
public static class ImageExtensions
/// <summary>Resizes an image to a new width and height value.</summary>
/// <param name="image">The image to resize.</param>
/// <param name="newWidth">The width of the new image.</param>
/// <param name="newHeight">The height of the new image.</param>
/// <param name="mode">Interpolation mode.</param>
/// <param name="maintainAspectRatio">If true, the image is centered in the middle of the returned image, maintaining the aspect ratio of the original image.</param>
/// <returns>The new image. The old image is unaffected.</returns>
public static Image ResizeImage(this Image image, int newWidth, int newHeight, InterpolationMode mode = InterpolationMode.Default, bool maintainAspectRatio = false)
Bitmap output = new Bitmap(newWidth, newHeight, image.PixelFormat);
using (Graphics gfx = Graphics.FromImage(output))
gfx.Clear(Color.FromArgb(0, 0, 0, 0));
gfx.InterpolationMode = mode;
if (mode == InterpolationMode.NearestNeighbor)
gfx.PixelOffsetMode = PixelOffsetMode.HighQuality;
gfx.SmoothingMode = SmoothingMode.HighQuality;
double ratioW = (double)newWidth / (double)image.Width;
double ratioH = (double)newHeight / (double)image.Height;
double ratio = ratioW < ratioH ? ratioW : ratioH;
int insideWidth = (int)(image.Width * ratio);
int insideHeight = (int)(image.Height * ratio);
gfx.DrawImage(image, new Rectangle((newWidth / 2) - (insideWidth / 2), (newHeight / 2) - (insideHeight / 2), insideWidth, insideHeight));
return output;
【讨论】：
没有使用maintainAspectRatio的参数。【参考方案8】：注意：此代码调整大小并删除纵横比之外的所有内容，而不是填充它..
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
namespace MyPhotos.Common
public class ThumbCreator
public enum VerticalAlign
Top,
Middle,
Bottom
public enum HorizontalAlign
Left,
Middle,
Right
public void Convert(string sourceFile, string targetFile, ImageFormat targetFormat, int height, int width, VerticalAlign valign, HorizontalAlign halign)
using (Image img = Image.FromFile(sourceFile))
using (Image targetImg = Convert(img, height, width, valign, halign))
string directory = Path.GetDirectoryName(targetFile);
if (!Directory.Exists(directory))
Directory.CreateDirectory(directory);
if (targetFormat == ImageFormat.Jpeg)
SaveJpeg(targetFile, targetImg, 100);
else
targetImg.Save(targetFile, targetFormat);
/// <summary>
/// Saves an image as a jpeg image, with the given quality
/// </summary>
/// <param name="path">Path to which the image would be saved.</param>
// <param name="quality">An integer from 0 to 100, with 100 being the
/// highest quality</param>
public static void SaveJpeg(string path, Image img, int quality)
if (quality < 0 || quality > 100)
throw new ArgumentOutOfRangeException("quality must be between 0 and 100.");
// Encoder parameter for image quality
EncoderParameter qualityParam =
new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
// Jpeg image codec
ImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
EncoderParameters encoderParams = new EncoderParameters(1);
encoderParams.Param[0] = qualityParam;
img.Save(path, jpegCodec, encoderParams);
/// <summary>
/// Returns the image codec with the given mime type
/// </summary>
private static ImageCodecInfo GetEncoderInfo(string mimeType)
// Get image codecs for all image formats
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
// Find the correct image codec
for (int i = 0; i < codecs.Length; i++)
if (codecs[i].MimeType == mimeType)
return codecs[i];
return null;
public Image Convert(Image img, int height, int width, VerticalAlign valign, HorizontalAlign halign)
Bitmap result = new Bitmap(width, height);
using (Graphics g = Graphics.FromImage(result))
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
float ratio = (float)height / (float)img.Height;
int temp = (int)((float)img.Width * ratio);
if (temp == width)
//no corrections are needed!
g.DrawImage(img, 0, 0, width, height);
return result;
else if (temp > width)
//den e för bred!
int overFlow = (temp - width);
if (halign == HorizontalAlign.Middle)
g.DrawImage(img, 0 - overFlow / 2, 0, temp, height);
else if (halign == HorizontalAlign.Left)
g.DrawImage(img, 0, 0, temp, height);
else if (halign == HorizontalAlign.Right)
g.DrawImage(img, -overFlow, 0, temp, height);
else
//den e för hög!
ratio = (float)width / (float)img.Width;
temp = (int)((float)img.Height * ratio);
int overFlow = (temp - height);
if (valign == VerticalAlign.Top)
g.DrawImage(img, 0, 0, width, temp);
else if (valign == VerticalAlign.Middle)
g.DrawImage(img, 0, -overFlow / 2, width, temp);
else if (valign == VerticalAlign.Bottom)
g.DrawImage(img, 0, -overFlow, width, temp);
return result;
【讨论】：
@Peter 这不符合我传递给函数的原始定义的大小宽度/高度。我得到了一个非常纤细和长的图像，知道如何解决这个问题吗？ @IdanShechter 这是一个老旧的答案（我已经很多年没有使用过这个代码了），你能给我一个例子，我可以帮助你。 @Peter 谢谢，我实际上正在使用 ImageProcessor，但我得到了一个例外：***.com/questions/51280935/…【参考方案9】：
// This allows us to resize the image. It prevents skewed images and
// also vertically long images caused by trying to maintain the aspect
// ratio on images who's height is larger than their width
public void ResizeImage(string OriginalFile, string NewFile, int NewWidth, int MaxHeight, bool OnlyResizeIfWider)
System.Drawing.Image FullsizeImage = System.Drawing.Image.FromFile(OriginalFile);
// Prevent using images internal thumbnail
FullsizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);
FullsizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);
if (OnlyResizeIfWider)
if (FullsizeImage.Width <= NewWidth)
NewWidth = FullsizeImage.Width;
int NewHeight = FullsizeImage.Height * NewWidth / FullsizeImage.Width;
if (NewHeight > MaxHeight)
// Resize with height instead
NewWidth = FullsizeImage.Width * MaxHeight / FullsizeImage.Height;
NewHeight = MaxHeight;
System.Drawing.Image NewImage = FullsizeImage.GetThumbnailImage(NewWidth, NewHeight, null, IntPtr.Zero);
// Clear handle to original file so that we can overwrite it if necessary
FullsizeImage.Dispose();
// Save resized picture
NewImage.Save(NewFile);
【讨论】：
您有没有使用 GetThumbnailImage 的示例？我想手动控制质量和其他设置。【参考方案10】：我创建了一个比发布的答案更简单的扩展方法。 并且在不裁剪图像的情况下应用纵横比。
public static Image Resize(this Image image, int width, int height)
var scale = Math.Min(height / (float)image.Height, width / (float)image.Width);
return image.GetThumbnailImage((int)(image.Width * scale), (int)(image.Height * scale), () => false, IntPtr.Zero);
示例用法：
using (var img = Image.FromFile(pathToOriginalImage))
using (var thumbnail = img.Resize(60, 60))
// Here you can do whatever you need to do with thumnail
【讨论】：
最好不要使用 ThumbnailImage。请改用图片。 图片的高度和宽度在 System.Drawing.Image 命名空间中是不可设置的，所以你不能只使用图片来代替。这只适用于旧的 Windows 窗体，它与这里讨论的命名空间不同。【参考方案11】：保持纵横比，消除信箱和邮筒。
static Image FixedSize(Image imgPhoto, int Width, int Height)
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int X = 0;
int Y = 0;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)Width / (float)sourceWidth);
nPercentH = ((float)Height / (float)sourceHeight);
if (nPercentH < nPercentW)
nPercent = nPercentH;
else
nPercent = nPercentW;
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap bmPhoto = new Bitmap(destWidth, destHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
imgPhoto.VerticalResolution);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.DrawImage(imgPhoto,
new Rectangle(X, Y, destWidth, destHeight),
new Rectangle(X, Y, sourceWidth, sourceHeight),
GraphicsUnit.Pixel);
grPhoto.Dispose();
return bmPhoto;
【讨论】：
【参考方案12】：public static void resizeImage_n_save(Stream sourcePath, string targetPath, int requiredSize)
using (var image = System.Drawing.Image.FromStream(sourcePath))
double ratio = 0;
var newWidth = 0;
var newHeight = 0;
double w = Convert.ToInt32(image.Width);
double h = Convert.ToInt32(image.Height);
if (w > h)
ratio = h / w * 100;
newWidth = requiredSize;
newHeight = Convert.ToInt32(requiredSize * ratio / 100);
else
ratio = w / h * 100;
newHeight = requiredSize;
newWidth = Convert.ToInt32(requiredSize * ratio / 100);
// var newWidth = (int)(image.Width * scaleFactor);
// var newHeight = (int)(image.Height * scaleFactor);
var thumbnailImg = new Bitmap(newWidth, newHeight);
var thumbGraph = Graphics.FromImage(thumbnailImg);
thumbGraph.CompositingQuality = CompositingQuality.HighQuality;
thumbGraph.SmoothingMode = SmoothingMode.HighQuality;
thumbGraph.InterpolationMode = InterpolationMode.HighQualityBicubic;
var imageRectangle = new Rectangle(0, 0, newWidth, newHeight);
thumbGraph.DrawImage(image, imageRectangle);
thumbnailImg.Save(targetPath, image.RawFormat);
//var img = FixedSize(image, requiredSize, requiredSize);
//img.Save(targetPath, image.RawFormat);
【讨论】：
【参考方案13】：我刚刚写了这篇文章，因为这里的答案都不够简单。您可以将硬编码的 128 替换为您想要的任何内容，或者将它们基于原始图像的大小。我想要的只是将图像重新缩放为 128x128 图像，保持纵横比并将结果居中在新图像中。
private Bitmap CreateLargeIconForImage(Bitmap src)
Bitmap bmp = new Bitmap(128, 128);
Graphics g = Graphics.FromImage(bmp);
float scale = Math.Max((float)src.Width / 128.0f, (float)src.Height / 128.0f);
PointF p = new PointF(128.0f - ((float)src.Width / scale), 128.0f - ((float)src.Height / scale));
SizeF size = new SizeF((float)src.Width / scale, (float)src.Height / scale);
g.DrawImage(src, new RectangleF(p, size));
return bmp;
【讨论】：
【参考方案14】：我知道这是一个较旧的线程。然而，这是谷歌搜索该主题的第一个结果。 没有一个答案符合我的要求。因此，这是我通过了解较旧的解决方案组合而成的解决方案，但将结果图像大小限制为最合适的高度和宽度。
double ratioW = (double)desiredWidthPixels / (double)originalImage.Width;
double ratioH = (double)desiredHeightPixels / (double)originalImage.Height;
double ratio = ratioW < ratioH ? ratioW : ratioH;
int suitableWidth = (int)(originalImage.Width * ratio);
int suitableHeight = (int)(originalImage.Height * ratio);
var resizedPhoto = new Bitmap((int)suitableWidth, (int)suitableHeight);
var graphicsSurface = Graphics.FromImage(resizedPhoto);
graphicsSurface.DrawImage(originalImage, new RectangleF(new PointF(0,0), new SizeF(suitableWidth, suitableHeight)));
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