EmguCV -如何指定jpeg质量时保存图像
本文关键字:保存 图像 jpeg 何指定 EmguCV | 更新日期: 2023-09-27 18:12:28
我使用以下c# EmguCV代码保存jpeg图像:
Emgu.CV.Image<Gray, byte> image
...
image.Save("imageName.jpg");
但图像存储质量极低(每8x8像素1个颜色正方形)。
当我保存bmp时,所有的都是ok的:
Emgu.CV.Image<Gray, byte> image
...
image.Save("imageName.bmp");
如何提高jpeg质量时,使用Emgu.Cv.Image.Save
或我应该调用其他功能?为什么默认质量如此之低?
尝试在EmguCV论坛上询问,但无法访问
EMGU只有image. save (filename),因此您必须使用。net方法保存图像。这个代码是从这里派生出来的。为了方便起见,我将代码分开,这段代码打开一个文件,然后尝试保存它。这是您感兴趣的函数saveJpeg(SaveFile)。FileName, img.ToBitmap(), 100);。基于函数saveJpeg(字符串路径,位图图像,长质量)。
open.Filter = "Image Files (*.tif; *.dcm; *.jpg; *.jpeg; *.bmp)|*.tif; *.dcm; *.jpg; *.jpeg; *.bmp";
if (open.ShowDialog() == DialogResult.OK)
{
Image<Bgr, Byte> img = new Image<Bgr, Byte>(open.FileName);
SaveFileDialog SaveFile = new SaveFileDialog();
if (SaveFile.ShowDialog() == DialogResult.OK)
{
saveJpeg(SaveFile.FileName, img.ToBitmap(), 100);
}
}
现在,要从下面得到该函数的代码,您可以将其复制并粘贴到您的项目中,不要忘记代码顶部的using语句。
using System.Drawing.Imaging;
private void saveJpeg(string path, Bitmap img, long quality)
{
// Encoder parameter for image quality
EncoderParameter qualityParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
// Jpeg image codec
ImageCodecInfo jpegCodec = this.getEncoderInfo("image/jpeg");
if (jpegCodec == null)
return;
EncoderParameters encoderParams = new EncoderParameters(1);
encoderParams.Param[0] = qualityParam;
img.Save(path, jpegCodec, encoderParams);
}
private 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;
}
这是EMGU最好的方法,如果你卡住了,告诉我。
希望有帮助,
克里斯在Chris的回答的基础上,如果有人感兴趣,这里有一个简单的扩展;
using System;
using System.Linq;
using System.Drawing.Imaging;
using Emgu.CV.Structure;
public static class EmguImageSave
{
/// <summary>
/// Save a jpeg image with a specified quality
/// </summary>
/// <param name="path">Name of the file to which to save the image</param>
/// <param name="quality">Byte that specifies JPEG Quality of the image encoder</param>
public static void Save( this Emgu.CV.Image<Bgr, Byte> img, string filename, double quality )
{
var encoderParams = new EncoderParameters( 1 );
encoderParams.Param[0] = new EncoderParameter(
System.Drawing.Imaging.Encoder.Quality,
(long)quality
);
var jpegCodec = (from codec in ImageCodecInfo.GetImageEncoders()
where codec.MimeType == "image/jpeg"
select codec).Single();
img.Bitmap.Save( filename, jpegCodec, encoderParams );
}
}
使用;
var fname = 0;
while( true )
{
try
{
var img = capture.QueryFrame();
img.Save( String.Format( @"c:'rec'{0}.jpg", ++fname), 100 );
} catch( Exception ) { break; }
}
我是这样做的:
CvInvoke.Imwrite(path, cvImage, new KeyValuePair<ImwriteFlags, int> (ImwriteFlags.JpegQuality, quality));
试试这个。为什么你不使用旧的和好的OpenCV http://opencv.itseez.com文档?
int quality = 100; // 0 - low, 100 - best
image.Save("imageName.bmp", CV_IMWRITE_JPEG_QUALITY, quality);