C#中将Bmp转换为jpg/png
C#中将Bmp转换为jpg/png
提问于 2008-09-03 13:29:58
有没有办法将bmp图像转换成jpg/png格式而不损失C#的质量？使用Image类我们可以将bmp转换成jpg格式，但是输出的图像质量很差。我们能获得像使用最高质量的photoshop转换为jpg的图像一样好的质量级别吗？
回答 7
Stack Overflow用户
回答已采纳
发布于 2008-09-03 13:39:52
var qualityEncoder = Encoder.Quality;
var quality = (long)<desired quality>;
var ratio = new EncoderParameter(qualityEncoder, quality );
var codecParams = new EncoderParameters(1);
codecParams.Param[0] = ratio;
var jpegCodecInfo = <one of the codec infos from ImageCodecInfo.GetImageEncoders() with mime type = "image/jpeg">;
bmp.Save(fileName, jpegCodecInfo, codecParams); // Save to JPGStack Overflow用户
发布于 2010-03-10 04:37:45
public static class BitmapExtensions
{
public static void SaveJPG100(this Bitmap bmp, string filename)
{
EncoderParameters encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);
bmp.Save(filename, GetEncoder(ImageFormat.Jpeg), encoderParameters);
}
public static void SaveJPG100(this Bitmap bmp, Stream stream)
{
EncoderParameters encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);
bmp.Save(stream, GetEncoder(ImageFormat.Jpeg), encoderParameters);
}
public static ImageCodecInfo GetEncoder(ImageFormat format)
{
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();
foreach (ImageCodecInfo codec in codecs)
{
if (codec.FormatID == format.Guid)
{
return codec;
}
}
return null;
}
}Stack Overflow用户
发布于 2012-01-03 01:34:49
jestro提供的BitmapExtensions很棒，我用了它们。然而，我想展示的是图像父类的修正版本，我认为它更方便，并提供了一种提供质量的方法：
public static class ImageExtensions
{
public static void SaveJpeg(this Image img, string filePath, long quality)
{
var encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality, quality);
img.Save(filePath, GetEncoder(ImageFormat.Jpeg), encoderParameters);
}
public static void SaveJpeg(this Image img, Stream stream, long quality)
{
var encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality, quality);
img.Save(stream, GetEncoder(ImageFormat.Jpeg), encoderParameters);
}
static ImageCodecInfo GetEncoder(ImageFormat format)
{
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();
return codecs.Single(codec => codec.FormatID == format.Guid);
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/41665
复制相关文章
相似问题