将 RawImage 保存到文件

Question

所以我设置了一个 RawImage 从 VR 耳机的直通摄像头捕获图像。

现在图片显示正确了，我要保存一下...

public class CameraCaptureBehaviour : MonoBehaviour
{
    private const string Tag = "[CAMERA_CAPTURE]";
    private const int CaptureFrequency = 500;
    [field:SerializeField] private RawImage CameraImage { get; set; }

    private int count = 0;

    private void Update()
    {
        if (++count % CaptureFrequency != 0) return;
        AndroidHelper.LogCat("Trying to get image", Tag);
        try
        {
            SaveImage();
        }
        catch (Exception e)
        {
            AndroidHelper.LogCat(e.Message, Tag);
        }
    }

    private void SaveImage()
    {
        var texture = CameraImage.texture;
        if (texture == null)
        {
            AndroidHelper.LogCat("No camera image found.", Tag);
            return;
        }

        var texture2d = (Texture2D) texture;
        var imageBytes = texture2d.EncodeToJPG();
        
        AndroidHelper.LogCat($"imageBytes is null: {imageBytes == null}", Tag);
        if (imageBytes == null) return;
        
        var filename = DateTime.Now.ToString("yyyyMMddHHmmssffff") + ".jpg";
        var filepath = Path.Combine(Application.persistentDataPath, filename);
        AndroidHelper.LogCat($"{imageBytes.Length} to {filepath}", Tag);
        try
        {
            File.WriteAllBytes(filepath, imageBytes);
            AndroidHelper.LogCat("SAVED", Tag);
        }
        catch (Exception e)
        {
            AndroidHelper.LogCat(e.Message, Tag);
        }
    }
}

这给了我

[CAMERA_CAPTURE] Trying to get image
[CAMERA_CAPTURE] imageBytes is null: False
[CAMERA_CAPTURE] 0 to /storage/emulated/0/Android/data/my.app/files/202203290841482532.png
[CAMERA_CAPTURE] SAVED

我不知道为什么图像应该是空的。

让我们尝试 Convert Color32 array to byte array to send over network 建议的 Color32 事情：

public class CameraCaptureBehaviour : MonoBehaviour
{
    private const string Tag = "[CAMERA_CAPTURE]";
    private const int CaptureFrequency = 500;
    [field:SerializeField] private RawImage CameraImage { get; set; }

    private int count = 0;

    private void Update()
    {
        if (++count % CaptureFrequency != 0) return;
        AndroidHelper.LogCat("Trying to get image", Tag);
        try
        {
            SaveImage();
        }
        catch (Exception e)
        {
            AndroidHelper.LogCat(e.Message, Tag);
        }
    }

    private void SaveImage()
    {
        var texture = CameraImage.texture;
        if (texture == null)
        {
            AndroidHelper.LogCat("No camera image found.", Tag);
            return;
        }

        var texture2d = (Texture2D) texture;

        var color32 = new Color32Array();
        color32.colors = texture2d.GetPixels32();
        var imageBytes = color32.byteArray;
        
        AndroidHelper.LogCat($"imageBytes is null: {imageBytes == null}", Tag);
        if (imageBytes == null) return;
        
        var filename = DateTime.Now.ToString("yyyyMMddHHmmssffff") + ".jpg";
        var filepath = Path.Combine(Application.persistentDataPath, filename);
        AndroidHelper.LogCat($"{imageBytes.Length} to {filepath}", Tag);
        try
        {
            File.WriteAllBytes(filepath, imageBytes);
            AndroidHelper.LogCat("SAVED", Tag);
        }
        catch (Exception e)
        {
            AndroidHelper.LogCat(e.Message, Tag);
        }
    }
}

[StructLayout(LayoutKind.Explicit)]
public struct Color32Array
{
    [FieldOffset(0)]
    public byte[] byteArray;

    [FieldOffset(0)]
    public Color32[] colors;
}

这给了我

[CAMERA_CAPTURE] Trying to get image
[CAMERA_CAPTURE] Texture '' is not configured correctly to allow GetPixels

我还发现 https://answers.unity.com/questions/1503328/save-rawimage-texture-to-file.html 与所有听起来正是您需要但几年前被问到的问题一样，完全没有有用的信息。

我只是想把我正在看的血腥画面保存在护目镜里，这也太难了吧？！

一些帮助将不胜感激。

如何保存 RawImage？

（注意：texture.GetType().FullName 给我 UnityEngine.Texture2D）

（注意：我取回后查看了贴图大小，是600x600所以图片不只是0像素大）

Answer 1

你可以调用 texture2d.EncodeToJPG 到 texture2D，你做对了。但是，您不能将任何纹理投射到 texture2D 中。嗯，你可以，但事情不一定会成功，因为你自己想通了;)

要将 RENDERtexture 转换为 Texture2D，您可以执行以下操作：

RenderTexture.active = texture;
Texture2D texture2d = new Texture2D(texture.width, texture.height);
texture2d.ReadPixels(new Rect(0, 0, texture.width, texture.height),0, 0);
texture2d.Apply();
RenderTexture.active = null;

如果这不起作用，您可以像 derHugo 指出的那样尝试 Graphics.CopyTexture()，或者 google 将您拥有的特定纹理类型转换为 Texture2D

Answer 2

我认为您不能简单地将 RawImage.texture 转换为 Texture2D。尝试像

这样实际复制它

var texture2d = new Texture2D(texture.width, texture.hight);
Graphics.CopyTexture(texture, texture2d);

见Graphics.CopyTexture

Answer 3

Blit 您的图像到 RenderTexture，然后使用 that 创建一个新的 Texture2D

private static Texture2D GetReadableTexture2d(Texture texture)
{
    var tmp = RenderTexture.GetTemporary(
        texture.width,
        texture.height,
        0,
        RenderTextureFormat.Default,
        RenderTextureReadWrite.Linear
    );
    Graphics.Blit(texture, tmp);

    var previousRenderTexture = RenderTexture.active;
    RenderTexture.active = tmp;

    var texture2d = new Texture2D(texture.width, texture.height);
    texture2d.ReadPixels(new Rect(0, 0, texture.width, texture.height), 0, 0);
    texture2d.Apply();

    RenderTexture.active = previousRenderTexture;
    RenderTexture.ReleaseTemporary(tmp);
    return texture2d;
}

结果 Texture2D 然后可以 EncodeToPNG 并保存：

public void SaveImage()
{
    SaveImage(GetReadableTexture2d(CameraImage.texture));
}

private static void SaveImage(Texture2D texture)
{
    var imageBytes = texture.EncodeToPNG();

    if (imageBytes.Length == 0)
    {
        AndroidHelper.LogCat($"Trying to save empty picture. Abort.", Tag);
        return;
    }

    var filename = DateTime.Now.ToString("yyyyMMddHHmmssffff") + ".png";
    var filepath = Path.Combine(Application.persistentDataPath, filename);
    AndroidHelper.LogCat($"{imageBytes.Length} to {filepath}", Tag);
    try
    {
        File.WriteAllBytes(filepath, imageBytes);
        AndroidHelper.LogCat("SAVED", Tag);
    }
    catch (Exception e)
    {
        AndroidHelper.LogCat(e.Message, Tag);
    }
}

不确定是否有更简单的方法，但至少这个方法似乎可行。

将 RawImage 保存到文件

Save a RawImage to file

c#

textures

unity3d