什么';在C#NET中有什么好的像素化算法?
在C#NET中对图像进行像素化的好算法是什么?虽然我不知道这方面有什么好的算法,但我不得不写一些类似的东西。我使用的技术非常简单,但我认为对于大型图像来说效率不是很高。基本上,我会在5个像素块(或者你想要多大)中对图像进行颜色平均,然后使所有这些像素的颜色相同。您可以通过仅对对角线像素进行平均来加快速度,这将节省大量周期,但精度较低。一个简单但无效的解决方案是将大小调整为较小的大小,然后使用像素复制重新调整大小 更好的解决方案是(伪代码):什么';在C#NET中有什么好的像素化算法?,c#,.net,image-processing,C#,.net,Image Processing,在C#NET中对图像进行像素化的好算法是什么?虽然我不知道这方面有什么好的算法,但我不得不写一些类似的东西。我使用的技术非常简单,但我认为对于大型图像来说效率不是很高。基本上,我会在5个像素块(或者你想要多大)中对图像进行颜色平均,然后使所有这些像素的颜色相同。您可以通过仅对对角线像素进行平均来加快速度,这将节省大量周期,但精度较低。一个简单但无效的解决方案是将大小调整为较小的大小,然后使用像素复制重新调整大小 更好的解决方案是(伪代码): (时间O(n),额外空间(除了可变源图像):O(1))
(时间O(n),额外空间(除了可变源图像):O(1))
//在x轴上像素化(选择一个完整的k s.t.1这个家伙有一个非常好的算法。它的工作原理是取每个“块”中所有颜色的平均值
我今天刚刚在C#/GDI+中使用了他的实现:
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Drawing;
using System.Linq;
using System.Text;
/// <summary>
/// Applies a pixelation effect to an image.
/// </summary>
[SuppressMessage(
"Microsoft.Naming",
"CA1704",
Justification = "'Pixelate' is a word in my book.")]
public class PixelateEffect : EffectBase
{
/// <summary>
/// Gets or sets the block size, in pixels.
/// </summary>
private int blockSize = 10;
/// <summary>
/// Gets or sets the block size, in pixels.
/// </summary>
public int BlockSize
{
get
{
return this.blockSize;
}
set
{
if (value <= 1)
{
throw new ArgumentOutOfRangeException("value");
}
this.blockSize = value;
}
}
/// <summary>
/// Applies the effect by rendering it onto the target bitmap.
/// </summary>
/// <param name="source">The source bitmap.</param>
/// <param name="target">The target bitmap.</param>
public override void DrawImage(Bitmap source, Bitmap target)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (target == null)
{
throw new ArgumentNullException("target");
}
if (source.Size != target.Size)
{
throw new ArgumentException("The source bitmap and the target bitmap must be the same size.");
}
using (var graphics = Graphics.FromImage(target))
{
graphics.PageUnit = GraphicsUnit.Pixel;
for (int x = 0; x < source.Width; x += this.BlockSize)
{
for (int y = 0; y < source.Height; y += this.BlockSize)
{
var sums = new Sums();
for (int xx = 0; xx < this.BlockSize; ++xx)
{
for (int yy = 0; yy < this.BlockSize; ++yy)
{
if (x + xx >= source.Width || y + yy >= source.Height)
{
continue;
}
var color = source.GetPixel(x + xx, y + yy);
sums.A += color.A;
sums.R += color.R;
sums.G += color.G;
sums.B += color.B;
sums.T++;
}
}
var average = Color.FromArgb(
sums.A / sums.T,
sums.R / sums.T,
sums.G / sums.T,
sums.B / sums.T);
using (var brush = new SolidBrush(average))
{
graphics.FillRectangle(brush, x, y, (x + this.BlockSize), (y + this.BlockSize));
}
}
}
}
}
/// <summary>
/// A structure that holds sums for color averaging.
/// </summary>
private struct Sums
{
/// <summary>
/// Gets or sets the alpha component.
/// </summary>
public int A
{
get;
set;
}
/// <summary>
/// Gets or sets the red component.
/// </summary>
public int R
{
get;
set;
}
/// <summary>
/// Gets or sets the blue component.
/// </summary>
public int B
{
get;
set;
}
/// <summary>
/// Gets or sets the green component.
/// </summary>
public int G
{
get;
set;
}
/// <summary>
/// Gets or sets the total count.
/// </summary>
public int T
{
get;
set;
}
}
}
使用系统;
使用System.Collections.Generic;
使用System.Diagnostics.CodeAnalysis;
使用系统图;
使用System.Linq;
使用系统文本;
///
///将像素化效果应用于图像。
///
[抑制信息](
“Microsoft.Naming”,
“CA1704”,
正当性=“'Pixelate'是我书中的一个词。”)]
公共类PixelateEffect:EffectBase
{
///
///获取或设置块大小(以像素为单位)。
///
私有int blockSize=10;
///
///获取或设置块大小(以像素为单位)。
///
公共整数块大小
{
得到
{
返回此.blockSize;
}
设置
{
如果(值=震源宽度| y+yy>=震源高度)
{
继续;
}
var color=source.GetPixel(x+xx,y+yy);
总和.A+=颜色.A;
sums.R+=color.R;
sums.G+=color.G;
总和.B+=颜色.B;
sums.T++;
}
}
var average=Color.FromArgb(
sums.A/sums.T,
总和R/总和T,
总和G/总和T,
总额B/总额T);
使用(var笔刷=新的SolidBrush(平均))
{
FillRectangle(画笔,x,y,(x+this.BlockSize),(y+this.BlockSize));
}
}
}
}
}
///
///保存颜色平均值总和的结构。
///
私有结构和
{
///
///获取或设置alpha组件。
///
公共INTA
{
得到;
设置
}
///
///获取或设置红色组件。
///
公共INTR
{
得到;
设置
}
///
///获取或设置蓝色组件。
///
公共int B
{
得到;
设置
}
///
///获取或设置绿色组件。
///
公共INTG
{
得到;
设置
}
///
///获取或设置总计数。
///
公共int T
{
得到;
设置
}
}
}
注意清空器,在我的机器上工作等等。你希望“像素化”是什么意思?你需要多快?好的“收缩和扩展”工作很好,但速度相当慢。如果你只需要做一次,不要想入非非。
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Drawing;
using System.Linq;
using System.Text;
/// <summary>
/// Applies a pixelation effect to an image.
/// </summary>
[SuppressMessage(
"Microsoft.Naming",
"CA1704",
Justification = "'Pixelate' is a word in my book.")]
public class PixelateEffect : EffectBase
{
/// <summary>
/// Gets or sets the block size, in pixels.
/// </summary>
private int blockSize = 10;
/// <summary>
/// Gets or sets the block size, in pixels.
/// </summary>
public int BlockSize
{
get
{
return this.blockSize;
}
set
{
if (value <= 1)
{
throw new ArgumentOutOfRangeException("value");
}
this.blockSize = value;
}
}
/// <summary>
/// Applies the effect by rendering it onto the target bitmap.
/// </summary>
/// <param name="source">The source bitmap.</param>
/// <param name="target">The target bitmap.</param>
public override void DrawImage(Bitmap source, Bitmap target)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (target == null)
{
throw new ArgumentNullException("target");
}
if (source.Size != target.Size)
{
throw new ArgumentException("The source bitmap and the target bitmap must be the same size.");
}
using (var graphics = Graphics.FromImage(target))
{
graphics.PageUnit = GraphicsUnit.Pixel;
for (int x = 0; x < source.Width; x += this.BlockSize)
{
for (int y = 0; y < source.Height; y += this.BlockSize)
{
var sums = new Sums();
for (int xx = 0; xx < this.BlockSize; ++xx)
{
for (int yy = 0; yy < this.BlockSize; ++yy)
{
if (x + xx >= source.Width || y + yy >= source.Height)
{
continue;
}
var color = source.GetPixel(x + xx, y + yy);
sums.A += color.A;
sums.R += color.R;
sums.G += color.G;
sums.B += color.B;
sums.T++;
}
}
var average = Color.FromArgb(
sums.A / sums.T,
sums.R / sums.T,
sums.G / sums.T,
sums.B / sums.T);
using (var brush = new SolidBrush(average))
{
graphics.FillRectangle(brush, x, y, (x + this.BlockSize), (y + this.BlockSize));
}
}
}
}
}
/// <summary>
/// A structure that holds sums for color averaging.
/// </summary>
private struct Sums
{
/// <summary>
/// Gets or sets the alpha component.
/// </summary>
public int A
{
get;
set;
}
/// <summary>
/// Gets or sets the red component.
/// </summary>
public int R
{
get;
set;
}
/// <summary>
/// Gets or sets the blue component.
/// </summary>
public int B
{
get;
set;
}
/// <summary>
/// Gets or sets the green component.
/// </summary>
public int G
{
get;
set;
}
/// <summary>
/// Gets or sets the total count.
/// </summary>
public int T
{
get;
set;
}
}
}