如何在 Android 或 IOS Unity 中设置从 Image Capture by Camera 读取的纹理？

Question

I have try to build an app which need to use a camera to capture an image (Credit Card) and read the number from the image.

The number i need to read is card number, expire month, and year.

I use a free asset from here :

Native Camera For Android IOS

to capture an image.

Also i am using a google tesseract form designspark here :

Tesseract OCR Unity

to recognize a text from image.

But before trying to read a text from image i got a problem on reading a texture.

For detail my code below :

public void TakePicture(int maxSize)
    {
        if (NativeCamera.IsCameraBusy())
        {
            return;
        }
        else
        {
            NativeCamera.Permission permission = NativeCamera.TakePicture((path) =>
            {
                Debug.Log("Image path: " + path);
                if (path != null)
                {
                    // Create a Texture2D from the captured image                    
                    Texture2D texture = NativeCamera.LoadImageAtPath(path, maxSize);                          

                    if (texture == null)
                    {
                        Debug.Log("Couldn't load texture from " + path);
                        return;
                    }

                    TesseractWrapper_And tesseract = new TesseractWrapper_And();
                    string datapath = System.IO.Path.Combine(Application.persistentDataPath, "tessdata");
                    tesseract.Init("eng", datapath);

                    //Color32[] imageColors = texture.GetPixels32();
                    string result = tesseract.RecognizeFromTexture(texture, false);

                    //copy bufferColors to imageColors one by one with necessary logic.

                    Card_Number.text = result ?? "Error: " + tesseract.errorMsg;

                    // Assign texture to a temporary quad and destroy it after 5 seconds
                    GameObject quad = GameObject.CreatePrimitive(PrimitiveType.Quad);
                    quad.transform.position = Camera.main.transform.position + Camera.main.transform.forward * 2.5f;
                    quad.transform.forward = Camera.main.transform.forward;
                    quad.transform.localScale = new Vector3(1f, texture.height / (float)texture.width, 1f);

                    Material material = quad.GetComponent<Renderer>().material;
                    if (!material.shader.isSupported) // happens when Standard shader is not included in the build
                        material.shader = Shader.Find("Legacy Shaders/Diffuse");

                    material.mainTexture = texture;

                    Destroy(quad, 5f);

                    // If a procedural texture is not destroyed manually, 
                    // it will only be freed after a scene change
                    Destroy(texture, 5f);                   

                }
            }, maxSize);

            Debug.Log("Permission result: " + permission);
        }

    }

I got an error on the line :

string result = tesseract.RecognizeFromTexture(texture, false);

The error is :

AndroidPlayer(ADB@127.0.0.1:34999) UnityException: Texture '' is not readable, the texture memory can not be accessed from scripts. You can make the texture readable in the Texture Import Settings. at (wrapper managed-to-native) UnityEngine.Texture2D.GetPixels(UnityEngine.Texture2D,int,int,int,int,int) at UnityEngine.Texture2D.GetPixels (System.Int32 miplevel) [0x0002b] in <004fc436a9154f7fab4df9679445af6c>:0 at UnityEngine.Texture2D.GetPixels () [0x00001] in <004fc436a9154f7fab4df9679445af6c>:0 at OCR_Test+<>c__DisplayClass6_0.b__0 (System.String path) [0x00040] in F:\\Github\\Tesseract_OCR\\Assets\\script\\OCR_Test.cs:80
at NativeCameraNamespace.NCCameraCallbackAndroid.MediaReceiveCallback (System.String path) [0x0001d] in F:\\Github\\Tesseract_OCR\\Assets\\Plugins\\NativeCamera\\Android\\NCCameraCallbackAndroid.cs:30 at NativeCameraNamespace.NCCameraCallbackAndroid+<>c__DisplayClass3_0.b__0 () [0x00000] in F:\\Github\\Tesseract_OCR\\Assets\\Plugins\\NativeCamera\\Android\\NCCameraCallbackAndroid.cs:19 at NativeCameraNamespace.NCCallbackHelper.Update () [0x0001d] in F:\\Github\\Tesseract_OCR\\Assets\\Plugins\\NativeCamera\\Android\\NCCallbackHelper.cs:21 (Filename: <004fc436a9154f7fab4df9679445af6c> Line: 0)

The texture is not readable.

This is how and where the image captured and save to temporary disk.

Texture2D texture = NativeCamera.LoadImageAtPath(path, maxSize);

and the file was found in here :

Image path: /data/user/0/com.Creativire.OCR/cache/IMG_camera.jpg

Question :

How to make the texture readable since the image is capture directly from the camera so we cannot set it from inspector ?

How to set the google tesseract from designspark just recognize the number ?

For note : i have already try the designspark tesseract ocr with a file image save in the unity and it worked, just do not work when capture from camera directly.

Any explanation from you is very appreciate.

Thank You

Answer 1

好吧终于想通了，你只需要将不可读的属性更改为 false

Texture2D texture = NativeCamera.LoadImageAtPath(path, maxSize,false,true);