Image Quality Compromised

I have an image which is not displayed properly in the Unity. I have tried various formats: png, psd, jpeg. I have attached original image and a screenshot showing how that image is displayed in Unity. I tried “Advanced”, “Texture” and “GUI” in import setting. But I get similar result with all modes.

Original image:

Image in Unity under GUI mode:

Image in Unity under Advanced mode:

Image in Unity under Texture mode:

You should change the TextureType