我需要调整大小5000张图像,并将它们保存在一个单独的文件夹中。我有一段代码可以创建图片的缩小副本(从互联网上找到的):
Bitmap ResizeImage(System.Drawing.Image image, int width, int height)
{
var destRect = new System.Drawing.Rectangle(0, 0, width, height);
var destImage = new Bitmap(width, height);
destImage.SetResolution(image.HorizontalResolution, image.VerticalResolution);
using (var graphics = Graphics.FromImage(destImage))
{
graphics.CompositingMode = CompositingMode.SourceCopy;
graphics.CompositingQuality = CompositingQuality.HighQuality;
graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphics.SmoothingMode = SmoothingMode.HighQuality;
graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
using (var wrapMode = new ImageAttributes())
{
wrapMode.SetWrapMode(WrapMode.TileFlipXY);
graphics.DrawImage(image, destRect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, wrapMode);
}
}
return destImage;
}
我有这段代码,首先创建所有必要的目录来保存图片,然后开始更改所有的图片并将它们保存到新的文件夹中。在执行程序的过程中,我的内存开始填充,直到达到大约590MB(1800张图片)的标记,然后抛出OutOfMemoryException错误。
void ResizeAllImages()
{
var files = Directory.GetFiles(ImagesDirectory, "*", SearchOption.AllDirectories);
if (!Directory.Exists(ResizedImagesDirectory)) Directory.CreateDirectory(ResizedImagesDirectory);
var dirs = Directory.GetDirectories(ImagesDirectory);
foreach(var d in dirs) Directory.CreateDirectory(System.IO.Path.Combine(ResizedImagesDirectory, System.IO.Path.GetFileName(d)));
foreach(var f in files)
{
using(var image = ResizeImage(System.Drawing.Image.FromFile(f), 224, 224))
{
var imgName = System.IO.Path.GetFileName(f);
var dirName = System.IO.Path.GetFileName(System.IO.Path.GetDirectoryName(f));
image.Save(System.IO.Path.Combine(ResizedImagesDirectory, dirName, imgName), ImageFormat.Png);
}
}
}
为解决这个问题,我尝试在foreach中添加以下2行代码:
GC.Collect();
GC.WaitForPendingFinalizers();
性能分析器显示,在整个程序操作期间,该进程占用的内存大约为50MB,但是当达到前一个标记(约1800张图像)时,又出现了OutOfMemoryException异常。请问如何解决这个问题。谢谢!
ResizeImage
方法,通过直接在循环中使用其代码或将位图实例作为参数传递来进行优化。Graphics 也应该采取同样的做法。 - user12031933