从透明表单上的图像中删除轮廓 [英] Remove outline from image on transparent form

问题描述

我正在尝试将窗口形式转换为透明形式，并使其仅显示一个对象.但是它在我的对象周围仍然有一条线(笔划)，并不是我想要的那样完美.如何取出线(行程)?(附有图片进行比较.)

I'm trying to transfer window form into transparent, and make it show just an object. But it still has a line (stroke) around my object, it's not really perfect as I wanted. How can I take out the line (stroke)? (Attached a picture to compare.)

这是我的代码:

private void Form1_Load(object sender, EventArgs e)
{
    this.FormBorderStyle = FormBorderStyle.None;
    this.Width = this.pictureBox1.Width;
    this.Height = this.pictureBox1.Height;
    SetStyle(ControlStyles.SupportsTransparentBackColor, true);
    this.BackColor = Color.Black;
    this.TransparencyKey = this.pictureBox1.BackColor;
}

推荐答案

您的图像具有半透明像素. TransparencyKey 将仅使一种颜色透明.因此，边界线像素将显示图像颜色和 Parent 控件或表单的颜色的混合.

Your image has semi-transparent pixels. TransparencyKey will only make one color transparent. So the borderline pixels will show a mix of the image color and the color of the Parent control or form..

这是通过使所有半透明像素完全透明来消除它们的功能:

Here is a function that eliminates all semi-transparent pixels by making them fully transparent:

using System.Runtime.InteropServices;
..

public static void UnSemi(Bitmap bmp)
{
    Size s = bmp.Size;
    PixelFormat fmt = bmp.PixelFormat;
    Rectangle rect = new Rectangle(Point.Empty, s);
    BitmapData bmpData = bmp.LockBits(rect, ImageLockMode.ReadOnly, fmt);
    int size1 = bmpData.Stride * bmpData.Height;
    byte[] data = new byte[size1];
    System.Runtime.InteropServices.Marshal.Copy(bmpData.Scan0, data, 0, size1);
    for (int y = 0; y < s.Height; y++)
    {
        for (int x = 0; x < s.Width; x++)
        {
            int index = y * bmpData.Stride + x * 4;
             // alpha,  threshold = 255
            data[index + 3] = (data[index + 3] < 255) ? (byte)0 : (byte)255; 
        }
    }
    System.Runtime.InteropServices.Marshal.Copy(data, 0, bmpData.Scan0, data.Length);
    bmp.UnlockBits(bmpData);
}

请注意，这也意味着反锯齿的外观会变得有些粗糙.

Note that this also means that the nice anti-aliased look will get somewhat rough instead..

还请注意，该例程采用32位ARGB像素格式，就像 PNG 通常那样.

Also note that the routine assumes a 32 bit ARGB pixel-format, as PNGs will usually have.

最后请注意，由于图像的很多为 Black ，因此您应该选择其他颜色.紫红色在野外很少见，但在龙的世界中可能并非如此，您想要选择一些随机的颜色.

Finally note that since the image has a lot of Black you should pick a different color. Fuchsia is rather rare in the wild, but maybe not in the world of dragons and you want to pick some random color..

也:您要设置 pictureBox1.BackColor = Color.Transparent ..

最后:有时在函数签名中添加一个 threshold 参数以设置一个级别，从该级别可以完全打开或关闭alpha.

Finally: Sometimes it makes sense to add a threshold parameter to the function signature to set a level from which to turn alpha all on or off..

这是一个用法示例:

this.BackColor = Color.FromArgb(1,2,3,4);
this.TransparencyKey = this.BackColor;
UnSemi((Bitmap)this.pictureBox1.Image);

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