http://www.cnblogs.com/EndOfYear/p/4334952.html

先上代码：

using System.Threading;

using UnityEngine;

using System.IO;

using System.Collections;

public class TextureUtility

{

public class ThreadData

{

public int start;

public int end;

public ThreadData (int s, int e) {

start = s;

end = e;

}

}

private static Color[] texColors;

private static Color[] newColors;

private static int w;

private static float ratioX;

private static float ratioY;

private static int w2;

private static int finishCount;

private static Mutex mutex;

public static void ScalePoint (Texture2D tex, int newWidth, int newHeight)

{

ThreadedScale (tex, newWidth, newHeight, false);

}

public static void ScaleBilinear (Texture2D tex, int newWidth, int newHeight)

{

ThreadedScale (tex, newWidth, newHeight, true);

}

private static void ThreadedScale (Texture2D tex, int newWidth, int newHeight, bool useBilinear)

{

texColors = tex.GetPixels();

newColors = new Color[newWidth * newHeight];

if (useBilinear)

{

ratioX = 1.0f / ((float)newWidth / (tex.width-1));

ratioY = 1.0f / ((float)newHeight / (tex.height-1));

}

else {

ratioX = ((float)tex.width) / newWidth;

ratioY = ((float)tex.height) / newHeight;

}

w = tex.width;

w2 = newWidth;

var cores = Mathf.Min(SystemInfo.processorCount, newHeight);

var slice = newHeight/cores;

finishCount = 0;

if (mutex == null) {

mutex = new Mutex(false);

}

if (cores > 1)

{

int i = 0;

ThreadData threadData;

for (i = 0; i < cores-1; i++) {

threadData = new ThreadData(slice * i, slice * (i + 1));

ParameterizedThreadStart ts = useBilinear ? new ParameterizedThreadStart(BilinearScale) : new ParameterizedThreadStart(PointScale);

Thread thread = new Thread(ts);

thread.Start(threadData);

}

threadData = new ThreadData(slice*i, newHeight);

if (useBilinear)

{

BilinearScale(threadData);

}

else

{

PointScale(threadData);

}

while (finishCount < cores)

{

Thread.Sleep(1);

}

}

else

{

ThreadData threadData = new ThreadData(0, newHeight);

if (useBilinear)

{

BilinearScale(threadData);

}

else

{

PointScale(threadData);

}

}

tex.Resize(newWidth, newHeight);

tex.SetPixels(newColors);

tex.Apply();

}

public static void BilinearScale (System.Object obj)

{

ThreadData threadData = (ThreadData) obj;

for (var y = threadData.start; y < threadData.end; y++)

{

int yFloor = (int)Mathf.Floor(y * ratioY);

var y1 = yFloor * w;

var y2 = (yFloor+1) * w;

var yw = y * w2;

for (var x = 0; x < w2; x++) {

int xFloor = (int)Mathf.Floor(x * ratioX);

var xLerp = x * ratioX-xFloor;

newColors[yw + x] = ColorLerpUnclamped(ColorLerpUnclamped(texColors[y1 + xFloor], texColors[y1 + xFloor+1], xLerp),

ColorLerpUnclamped(texColors[y2 + xFloor], texColors[y2 + xFloor+1], xLerp),

y*ratioY-yFloor);

}

}

mutex.WaitOne();

finishCount++;

mutex.ReleaseMutex();

}

public static void PointScale (System.Object obj)

{

ThreadData threadData = (ThreadData) obj;

for (var y = threadData.start; y < threadData.end; y++)

{

var thisY = (int)(ratioY * y) * w;

var yw = y * w2;

for (var x = 0; x < w2; x++) {

newColors[yw + x] = texColors[(int)(thisY + ratioX*x)];

}

}

mutex.WaitOne();

finishCount++;

mutex.ReleaseMutex();

}

private static Color ColorLerpUnclamped (Color c1, Color c2, float value)

{

return new Color (c1.r + (c2.r - c1.r)*value,

c1.g + (c2.g - c1.g)*value,

c1.b + (c2.b - c1.b)*value,

c1.a + (c2.a - c1.a)*value);

}

public static Texture2D LoadTexture(string filePath) {

Texture2D tex = null;

byte[] fileData;

if (File.Exists(filePath)) {

fileData = File.ReadAllBytes(filePath);

tex = new Texture2D(2, 2,TextureFormat.ARGB32,false);

tex.LoadImage(fileData);

}

return tex;

}

// Save ScreenShot

public static void SaveScreenShotAsync(string path, Vector2 size)

{

SWMain.sharedSWMain.StartCoroutine(TextureUtility.SaveScreenShot(path, size));

}

public static void SaveScreenShotAsync(string path, Rect rect, Vector2 size)

{

SWMain.sharedSWMain.StartCoroutine(TextureUtility.SaveScreenShot(path, rect, size));

}

public static IEnumerator SaveScreenShot(string path, Vector2 size)

{

Rect rect = new Rect (0, 0, Screen.width, Screen.height);

yield return SWMain.sharedSWMain.StartCoroutine(TextureUtility.SaveScreenShot(path,rect, size));

}

public static IEnumerator SaveScreenShot(string path, Rect rect, Vector2 size = default(Vector2))

{

// We should only read the screen bufferafter rendering is complete

yield return new WaitForEndOfFrame();

// 要保存图片的大小

Texture2D tex = new Texture2D ((int)rect.width, (int)rect.height, TextureFormat.RGB24, false);

// 截取的区域

tex.ReadPixels(rect, 0, 0);

tex.Apply();

// 把图片数据转换为byte数组

if (size != default(Vector2))

{

ScaleBilinear(tex, (int)size.x, (int)size.y);

}

byte[] buffer = tex.EncodeToJPG (100);

Object.Destroy(tex);

// 然后保存为图片

File.WriteAllBytes(path, buffer);

}

public static Texture2D Copy(Texture2D tex)

{

return new Texture2D(tex.width, tex.height, tex.format, false);

}

///

/// Applies sepia effect to the texture.

///

/// Texture to process.

public static Texture2D SetSepia(Texture2D tex)

{

Texture2D t = Copy(tex);

Color[] colors = tex.GetPixels();

for (int i = 0; i < colors.Length; i++)

{

float alpha = colors[i].a;

float grayScale = ((colors[i].r * .299f) + (colors[i].g * .587f) + (colors[i].b * .114f));

Color c = new Color(grayScale, grayScale, grayScale);

colors[i] = new Color(c.r * 1, c.g * 0.95f, c.b * 0.82f, alpha);

}

t.SetPixels(colors);

t.Apply();

return t;

}

///

/// Applies grayscale effect to the texture and changes colors to grayscale.

///

/// Texture to process.

public static Texture2D SetGrayscale(Texture2D tex)

{

Texture2D t = Copy(tex);

Color[] colors = tex.GetPixels();

for (int i = 0; i < colors.Length; i++)

{

float val = (colors [i].r + colors [i].g + colors [i].b) / 3;

colors [i] = new Color(val, val, val);

}

t.SetPixels(colors);

t.Apply();

return t;

}

///

/// Pixelates the texture.

///

/// Texture to process.

/// Size of the pixel.

public static Texture2D SetPixelate(Texture2D tex, int size)

{

Texture2D t = Copy(tex);

Rect rectangle = new Rect(0, 0, tex.width, tex.height);

for (int xx = (int)rectangle.x; xx < rectangle.x + rectangle.width && xx < tex.width; xx += size)

{

for (int yy = (int)rectangle.y; yy < rectangle.y + rectangle.height && yy < tex.height; yy += size)

{

int offsetX = size / 2;

int offsetY = size / 2;

while (xx + offsetX >= tex.width) offsetX--;

while (yy + offsetY >= tex.height) offsetY--;

Color pixel = tex.GetPixel(xx + offsetX, yy + offsetY);

for (int x = xx; x < xx + size && x < tex.width; x++)

for (int y = yy; y < yy + size && y < tex.height; y++)

t.SetPixel(x, y, pixel);

}

}

t.Apply();

return t;

}

///

/// Inverts colors of the texture.

///

/// Texture to process.

public static Texture2D SetNegative(Texture2D tex)

{

Texture2D t = Copy(tex);

Color[] colors = tex.GetPixels();

Color pixel;

for (int i = 0; i < colors.Length; i++)

{

pixel = colors[i];

colors[i] = new Color(1 - pixel.r, 1 - pixel.g, 1 - pixel.b);

}

t.SetPixels(colors);

t.Apply();

return t;

}

///

/// Sets the foggy effect.雾化效果

///

/// texture processed.

/// texture to process.

public static Texture2D SetFoggy(Texture2D tex)

{

Texture2D t = Copy(tex);

Color pixel;

for (int x = 1; x < tex.width - 1; x++)

for (int y = 1; y < tex.height - 1; y++)

{

int k = UnityEngine.Random.Range(0, 123456);

//像素块大小

int dx = x + k % 19;

int dy = y + k % 19;

if (dx >= tex.width)

dx = tex.width - 1;

if (dy >= tex.height)

dy = tex.height - 1;

pixel = tex.GetPixel(dx, dy);

t.SetPixel(x, y, pixel);

}

t.Apply();

return t;

}

///

/// Sets the soft effect.柔化效果

///

/// texture processed.

/// texture to process.

public static Texture2D SetSoft(Texture2D tex)

{

Texture2D t = Copy(tex);

int[] Gauss = { 1, 2, 1, 2, 4, 2, 1, 2, 1 };

for (int x = 1; x < tex.width - 1; x++)

for (int y = 1; y < tex.height - 1; y++)

{

float r = 0, g = 0, b = 0;

int Index = 0;

for (int col = -1; col <= 1; col++)

for (int row = -1; row <= 1; row++)

{

Color pixel = tex.GetPixel(x + row, y + col);

r += pixel.r * Gauss[Index];

g += pixel.g * Gauss[Index];

b += pixel.b * Gauss[Index];

Index++;

}

r /= 16;

g /= 16;

b /= 16;

//处理颜色值溢出

r = r > 1 ? 1 : r;

r = r < 0 ? 0 : r;

g = g > 1 ? 1 : g;

g = g < 0 ? 0 : g;

b = b > 1 ? 1 : b;

b = b < 0 ? 0 : b;

t.SetPixel(x - 1, y - 1, new Color(r, g, b));

}

t.Apply();

return t;

}

///

/// Sets the sharp.锐化效果

///

/// The sharp.

/// Tex.

public static Texture2D SetSharp(Texture2D tex)

{

Texture2D t = Copy(tex);

Color pixel;

//拉普拉斯模板

int[] Laplacian ={ -1, -1, -1, -1, 9, -1, -1, -1, -1 };

for (int x = 1; x < tex.width - 1; x++)

for (int y = 1; y < tex.height - 1; y++)

{

float r = 0, g = 0, b = 0;

int index = 0;

for (int col = -1; col <= 1; col++)

for (int row = -1; row <= 1; row++)

{

pixel = tex.GetPixel(x + row, y + col); r += pixel.r * Laplacian[index];

g += pixel.g * Laplacian[index];

b += pixel.b * Laplacian[index];

index++;

}

//处理颜色值溢出

r = r > 1 ? 1 : r;

r = r < 0 ? 0 : r;

g = g > 1 ? 1 : g;

g = g < 0 ? 0 : g;

b = b > 1 ? 1 : b;

b = b < 0 ? 0 : b;

t.SetPixel(x - 1, y - 1, new Color(r, g, b));

}

t.Apply();

return t;

}

///

/// Sets the relief.浮雕效果

///

/// The relief.

/// Tex.

public static Texture2D SetRelief(Texture2D tex)

{

Texture2D t = Copy(tex);

for (int x = 0; x < tex.width - 1; x++)

{

for (int y = 0; y < tex.height - 1; y++)

{

float r = 0, g = 0, b = 0;

Color pixel1 = tex.GetPixel(x, y);

Color pixel2 = tex.GetPixel(x + 1, y + 1);

r = Mathf.Abs(pixel1.r - pixel2.r + 0.5f);

g = Mathf.Abs(pixel1.g - pixel2.g + 0.5f);

b = Mathf.Abs(pixel1.b - pixel2.b + 0.5f);

if (r > 1)

r = 1;

if (r < 0)

r = 0;

if (g > 1)

g = 1;

if (g < 0)

g = 0;

if (b > 1)

b = 1;

if (b < 0)

b = 0;

t.SetPixel(x, y, new Color(r, g, b));

}

}

t.Apply();

return t;

}

}

如何调用：

1. 压缩图片：

TextureUtility.ScalePoint(Texture2D tex, int newWidth, int newHeight),第一个参数是要传入的Texture2D, 第二个参数是新的图片的宽度，第三个参数则是新的图片的高度。也可以调用TextureUtility.ScaleBilinear(Texture2D tex, int newWidth, int newHeight)。

2. 截屏：

yield return StartCoroutine(TextureUtility.SaveScreenShot(string path, Vector2 size, Vector2 size = default(Vector2)))

或者调用异步方法TextureUtility.SaveScreenShotAsync(string path, Rect rect, Vector2 size)

3. 图片滤镜：

如灰阶滤镜：TextureUtility.SetGrayscale(Texture2D tex)；

底片滤镜：TextureUtility.SetNegative(Texture2D tex)等。