How to solve memory leak in Unity3d for textures?

Question

Unity

In Unity, it was necessary to convert the image from the camera to png and then send it over the socket. For this, RenderTexture was used and here is a piece of code.

byte[] RenderTextureToPng(RenderTexture rt)
    {
        Texture2D png_tex = new Texture2D(512, 512, TextureFormat.RGB24, false);
        RenderTexture.active = rt;
        png_tex.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
        png_tex.Apply();
        return png_tex.EncodeToPNG();
    }

But it suddenly turned out that after starting the program, the space occupied by Texture in the Memory tab began to increase sharply, loading all possible memory (even the system fell from this the first time I didn’t notice).
What could it be? When the code for calling this function is commented, everything is fine.

Answer 1

Solution:
https://forum.kerbalspaceprogram.com/index.php?/to...
It was a constant announcement
Although I still do not fully understand why it is not removed by the garbage collector ..