如何从字节数组创建图像并显示它？

Question

我想从图像文件中获取数据并在 Unity 可以读取的纹理中显示该信息。

我能够将像素信息放入字节数组，但屏幕上什么也没有显示。我如何实际显示图像？

     pcxFile = File.ReadAllBytes("Assets/5_ImageParser/bagit_icon.pcx");
     int startPoint = 128;
     int height = 152; 
     int width = 152; 
     target = new Texture2D(height, width);
     for (var y = 0; y < height; y++)
     {
         for (var x = 0; x < width; x++)
         {
             timesDone ++;
             pixels[x, y] = new Color(pcxFile[startPoint], pcxFile[startPoint+1], pcxFile[startPoint+2]);
             startPoint += 4;
             target.SetPixel(x, y, pixels[x, y]);
         }            
     }
     target.Apply();
     target.EncodeToJPG();

Answer 1

好吧，（假设您正确获取了像素数据）您必须将创建的纹理分配给某物...

我会使用例如RawImage since it doesn't need a Sprite (as the UI.Image component would do - also see the RawImage Manual):

// Reference this in the Inspector
public RawImage image;

//...

pcxFile = File.ReadAllBytes("Assets/5_ImageParser/bagit_icon.pcx");
int startPoint = 128;
int height = 152; 
int width = 152; 
target = new Texture2D(height, width);
for (var y = 0; y < height; y++)
{
    for (var x = 0; x < width; x++)
    {
        timesDone ++;
        pixels[x, y] = new Color(pcxFile[startPoint], pcxFile[startPoint+1], pcxFile[startPoint+2]);
        startPoint += 4;
        target.SetPixel(x, y, pixels[x, y]);
    }            
}
target.Apply();
// You don't need this. Only if you are also going to save it locally
// as an actual *.jpg file or if you are going to
// e.g. upload it later via http POST
//
// In this case however you would have to asign the result 
// to a variable in order to use it later
//var rawJpgBytes = target.EncodeToJPG();

// Assign the texture to the RawImage component
image.texture = target;

或者与普通 Image 组件一起使用，使用 Sprite.Create:

从您的纹理创建一个 Sprite

// Reference this in the Inspector
public Image image;

// ...

var sprite = Sprite.Create(target, new Rect(0.0f, 0.0f, target.width, target.height), new Vector2(0.5f, 0.5f), 100.0f);

image.sprite = sprite;

提示 1
为了获得正确的宽高比，我通常使用了一个小技巧：

为此 RawImage 创建父对象
在父

RectTransform

在 RawImage/Image 旁边（在子对象上）添加 AspectRatioFitter (also see the AspectRatioFitter Manual) 并将 AspectMode 设置为 FitInParent.

现在在代码中调整纵横比（从纹理中获取）：

public RawImage image;
public AspectRatioFitter fitter;

//...

image.texture = target;

var ratio = target.width / target.height;
fitter.aspectRatio = ratio;

提示 2
对所有像素调用一次SetPixels比重复调用SetPixel"cheaper":

// ...

startPoint = 0;
pixels = new Color[width * height]();
for(int i = 0; i < pixels.Length; i++)
{
    pixels[i] = new Color(pcxFile[startPoint], pcxFile[startPoint+1], pcxFile[startPoint+2]);
    startPoint += 4;
}

target.SetPixels(pixels);
target.Apply();

// ...

（我不知道你的 pcx 格式是如何工作的，但也许你甚至可以使用 LoadRawTextureData

如何从字节数组创建图像并显示它？

How to create an image from byte array and display it?

c#

textures

texture2d

unity3d