Texture2D.GetPixels
GetPixels(miplevel: int = 0): Color[];
Color[] GetPixels(int miplevel = 0);
def GetPixels(miplevel as int = 0) as Color[]
Description

Get a block of pixel colors.

This function returns an array of pixel colors of the whole mip level of the texture.

The returned array is a flattened 2D array, where pixels are laid out left to right, bottom to top (i.e. row after row). Array size is width by height of the mip level used. The default mip level is zero (the base texture) in which case the size is just the size of the texture. In general case, mip level size is mipWidth=max(1,width>>miplevel) and similarly for height.

The texture must have the Read/Write Enabled flag set in the import settings, otherwise this function will fail.

Using GetPixels can be faster than calling GetPixel repeatedly, especially for large textures. In addition, GetPixels can access individual mipmap levels.
	// Get a rectangular area of a texture and place it into a new
	// texture the size of the rectangle.
	
	// Source texture and the rectangular area we want to extract.
	var sourceTex: Texture2D;
	var sourceRect: Rect;
	
	
	function Start () {
		// The values in the Rect structure are floats, so round them
		// down to the nearest integer.
		var x = Mathf.FloorToInt(sourceRect.x);
		var y = Mathf.FloorToInt(sourceRect.x);
		var width = Mathf.FloorToInt(sourceRect.width);
		var height = Mathf.FloorToInt(sourceRect.height);
		
		// Get the pixel block and place it into a new texture.
		var pix = sourceTex.GetPixels(x, y, width, height);
		var destTex = new Texture2D(width, height);
		destTex.SetPixels(pix);
		destTex.Apply();
		
		// Set the current object's texture to show the
		// extracted rectangle.
		renderer.material.mainTexture = destTex;
	}
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    public Texture2D sourceTex;
    public Rect sourceRect;
    void Start() {
        int x = Mathf.FloorToInt(sourceRect.x);
        int y = Mathf.FloorToInt(sourceRect.x);
        int width = Mathf.FloorToInt(sourceRect.width);
        int height = Mathf.FloorToInt(sourceRect.height);
        Color[] pix = sourceTex.GetPixels(x, y, width, height);
        Texture2D destTex = new Texture2D(width, height);
        destTex.SetPixels(pix);
        destTex.Apply();
        renderer.material.mainTexture = destTex;
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	public sourceTex as Texture2D

	public sourceRect as Rect

	def Start() as void:
		x as int = Mathf.FloorToInt(sourceRect.x)
		y as int = Mathf.FloorToInt(sourceRect.x)
		width as int = Mathf.FloorToInt(sourceRect.width)
		height as int = Mathf.FloorToInt(sourceRect.height)
		pix as (Color) = sourceTex.GetPixels(x, y, width, height)
		destTex as Texture2D = Texture2D(width, height)
		destTex.SetPixels(pix)
		destTex.Apply()
		renderer.material.mainTexture = destTex

GetPixels(x: int, y: int, blockWidth: int, blockHeight: int, miplevel: int = 0): Color[];
Color[] GetPixels(int x, int y, int blockWidth, int blockHeight, int miplevel = 0);
def GetPixels(x as int, y as int, blockWidth as int, blockHeight as int, miplevel as int = 0) as Color[]
Description

Get a block of pixel colors.

This function is an extended version of GetPixels above; it does not return the whole mip level but only blockWidth by blockHeight region starting at x,y. The block must fit into the used mip level. The returned array is blockWidth*blockHeight size.