Need help to change image texture position or display view on image target

HelloActually I am new on Vuforia SDK and open GL programming.I need help to change the coordinate/scale ratio, width, heght of image texture.I follow this guide to enable the texture on image target.https://developer.vuforia.com/resources/dev-guide/textured-plane-target

The texture is coming over the target images. But i want change the texture width/height, coordinates.My target image is:

Now I want to display a TextView on the image target like this.

https://developer.vuforia.com/sites/default/files/tiger_with_description.jpg

I am now doing this by displaying a texture which is same as target image with some modification.but I want to do this from android side.when target images found, then a TextView will appear on a relative point of that target image.and also disappear when camera move from that target image.If another target image found, then another TextView will appear. This will do dynamically.I also follow this:https://developer.vuforia.com/forum/android/get-trackable-anglebut when I getting the top-left corner and top-right coordinates (v1,v2), how to appear/disappear android layouts on that position?If any one have done this, please help me.Thanks.