如何压缩JPG图片？ [英] How to compress jpg image?

问题描述

我有3300K的大小的JPG图像格式。

I have jpg image format with size of 3300K.

我尽量压缩图像=>让我改变了图像大小，但我仍然有非常大的尺寸

I try to compress the image => so i changed the image size but still i have very big size of the file ( ~ 800K )

The change size method code:

改变大小的方法的代码>内部静态影像resizeImage（图片imgToResize）
{
位图b =新位图（300，300）;使用

（图形G = Graphics.FromImage（（图）B））
{
//g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.InterpolationMode = InterpolationMode.Low;

g.DrawImage（imgToResize，0，0，300，300）;

imgToResize.Dispose（）;
}

返回（图）B：
}

internal static Image resizeImage( Image imgToResize ) { Bitmap b = new Bitmap( 300, 300 ); using( Graphics g = Graphics.FromImage( ( Image )b ) ) { //g.InterpolationMode = InterpolationMode.HighQualityBicubic; g.InterpolationMode = InterpolationMode.Low; g.DrawImage( imgToResize, 0, 0, 300, 300 ); imgToResize.Dispose(); } return ( Image )b; }

我必须压缩图像 - 即使图像的质量将不太然后原稿。

I must compress the image - even if the quality of the image will be less then the original.

我该怎么办呢？

推荐答案

使用呼叫调整大小功能如下代码

mg = image

newsize = height and width

Call Resize function using following code

Bitmap mg = new Bitmap(strUploadPath);
Size newSize = new Size(Convert.ToInt32(DispMaxWidth), Convert.ToInt32(DispMaxHeight));
Bitmap bp = ResizeImage(mg, newSize);
if (bp != null)
bp.Save(strUploadPath, System.Drawing.Imaging.ImageFormat.Jpeg);

private Bitmap ResizeImage(Bitmap mg, Size newSize)
        {
            double ratio = 0d;
            double myThumbWidth = 0d;
            double myThumbHeight = 0d;
            int x = 0;
            int y = 0;

            Bitmap bp;

            if ((mg.Width / Convert.ToDouble(newSize.Width)) > (mg.Height /
            Convert.ToDouble(newSize.Height)))
                ratio = Convert.ToDouble(mg.Width) / Convert.ToDouble(newSize.Width);
            else
                ratio = Convert.ToDouble(mg.Height) / Convert.ToDouble(newSize.Height);
            myThumbHeight = Math.Ceiling(mg.Height / ratio);
            myThumbWidth = Math.Ceiling(mg.Width / ratio);

            //Size thumbSize = new Size((int)myThumbWidth, (int)myThumbHeight);
            Size thumbSize = new Size((int)newSize.Width, (int)newSize.Height);
            bp = new Bitmap(newSize.Width, newSize.Height);
            x = (newSize.Width - thumbSize.Width) / 2;
            y = (newSize.Height - thumbSize.Height);
            // Had to add System.Drawing class in front of Graphics ---
            System.Drawing.Graphics g = Graphics.FromImage(bp);
            g.SmoothingMode = SmoothingMode.HighQuality;
            g.InterpolationMode = InterpolationMode.HighQualityBicubic;
            g.PixelOffsetMode = PixelOffsetMode.HighQuality;
            Rectangle rect = new Rectangle(x, y, thumbSize.Width, thumbSize.Height);
            g.DrawImage(mg, rect, 0, 0, mg.Width, mg.Height, GraphicsUnit.Pixel);

            return bp;

        }

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