Android Question Horizontal and Vertical Image Scrolling

You could use a 2dcsv (not sure of the name) 2D custom scroll view...
It allows the inner panel to be scrollable in both vertical and horizontal directions

[FOUND IT] https://www.b4x.com/android/forum/threads/lib-scrollview2d.19268/

Thanks Cableguy

I've looked at the 2DCSV example but it seems that it works only on a single image and lets you move around and look at different areas of the single image.

That's not what I want. I want to be able to display one of the 800 images and have a button to replace the image with an adjacent image, sliding in from above, below left or right.

I guess that Erel's SlidingPanels example is the nearest thing to what I'm after, but I need to be able to slide panels vertically AND horizontally.

I hope someone can suggest a way of doing this.

You can always try to create your own custom view and make it act exactly as you want...
ie: place a panel to be the view parent (or use mBase for it) place an array of image views, and finally add a scrollbar to each side (V/H)
Then code away!

Additionally check if 800 images loaded at once may result in OOM.

256x256x4 byte = 256kb for each image approx. 4 = 1mb. At 800 images you´ll need about 200 mb of ram (probably OOM)