How to convert type 'UnityEngine.Color32[ ]' to 'UnityEngine.Sprite'

Question

I'm trying to generate a QR Code using ZXing.Net and at first I have the problem where the .Save() is not working because of an error CS1061. So, I scratched that idea then I tried to save .Write() as image then render it in unity but Unity returns an error:

Cannot implicitly convert type 'UnityEngine.Color32[]' to 'UnityEngine.Sprite'

I tried using the answer from here where they used Sprite.Create() as a solution but converted a Texture2D instead of a Color32[ ] but I wasn't able to confirm if the code worked for me since the code returns an error that:

The type or namespace name 'Image' could not be found

As I said, I wasn't able to find out if the code really worked or not. I don't know what caused the namespace error since the script I'm using is under the Image UI.

These are the codes I'm using:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using ZXing;
using ZXing.QrCode;
using System.Drawing;

public class SampleScript : MonoBehaviour
{

    public Texture2D myTexture;
    Sprite mySprite;
    Image myImage;

    void Main()
    {
        var qrWriter = new BarcodeWriter();
        qrWriter.Format = BarcodeFormat.QR_CODE;

        this.gameObject.GetComponent<SpriteRenderer>().sprite = qrWriter.Write("text");
    }

    public void FooBar()
    {
        mySprite = Sprite.Create(myTexture, new Rect(0.0f, 0.0f, myTexture.width, myTexture.height), new Vector2(0.5f, 0.5f), 100.0f);
        myImage.sprite = mySprite;
    }

    void Start()
    {
        FooBar();
        Main();
    }

I still haven't tested this code since the errors must first be resolved before running.

Answer 1

using UnityEngine;

public class ExampleScript : MonoBehaviour
{
    WebCamTexture webcamTexture;
    Color32[] data;
    public UIScreen screen;
    int HEIGHT, WIDTH;

    void Start()
    {
        // Start web cam feed
        webcamTexture = new WebCamTexture();
        webcamTexture.Play();
        HEIGHT = webcamTexture.height;
        WIDTH = webcamTexture.width;
        data = new Color32[WIDTH * HEIGHT];
    }

    void Update()
    {
        if (webcamTexture.didUpdateThisFrame)
        {
            webcamTexture.GetPixels32(data);
            var texture = new Texture2D(WIDTH, HEIGHT);
            texture.SetPixels32(data);
            texture.Apply();
            screen.imageUI.sprite = Sprite.Create(texture, new Rect(0, 0, texture.width, texture.height), Vector2.one * 0.5f, 100);
        }
    }
}

incase if anyone needs the entire code to convert and show webcam to imageUI/sprite screen.imageUI is just the Image ui element in canvas

Answer 2

The first

The type or namespace name 'Image' could not be found

is fixed by adding the according namespace

using UnityEngine.UI;

at the top of your file.

---

The exception

Cannot implicitly convert type 'UnityEngine.Color32[]' to 'UnityEngine.Sprite'

Can't simply be "fixed". It is as the exception tells you: You can't implicitly convert between those types .. not even explicitly.

 qrWriter.Write("text");

returns the Color32[].

---

What you can try to do is creating a Texture using this color information BUT you will allways have to know the pixel dimensions of the target texture.

Then you can use Texture2D.SetPixels32 like

var texture = new Texture2D(HIGHT, WIDTH);
texture.SetPixels32(qrWriter.Write("text"));
texture.Apply();
this.gameObject.GetComponent<SpriteRenderer>().sprite = Sprite.Create(texture, new Rect(0,0, texture.width, texture.height), Vector2.one * 0.5f, 100);

---

Possible that you also will actively have to pass in the EncodingOptions in order to set the desired pixel dimensions as shown in this blog:

using ZXing.Common;

...

BarcodeWriter qrWriter = new BarcodeWriter
{
    Format = BarcodeFormat.QR_CODE,
    Options = new EncodingOptions
    {
        Height = height,
        Width = width
    }
};
Color32[] pixels = qrWriter.Write("text");
Texture2D texture = new Texture2D(width, height);
texture.SetPixels32(pixels);
texture.Apply();

there you can also find some more useful information about threading and scaling of the texture etc.