B4A Library [B4X] HugeImageView - show very large images

Q: I want to load a 10,000 x 10,000 image?
A: That's impossible!!! The memory required is: width * height * 4 = 400MB.
A: You will need to scale down the image.
A: Sure. Use HugeImageView:


(image source: https://images4.alphacoders.com/655/655004.jpg)

How does it work?

It uses two layers - one with a scaled down image and another made of tiles. The visible tiles are loaded in the background using a native API that allows loading specific regions (BitmapRegionDecoder).

I've tested it with a 40,000x20,000 image and it worked (such image requires 3GB of RAM to fully load it).


Updates:
- v1.03 - Adds support for B4J.
- v1.02 - Fixes an issue related to image vs. device orientation (https://www.b4x.com/android/forum/threads/hugeimageview-tile-not-showing-at-bottom.134387/).
- v1.01 - Adds support for B4i.

 

[Erel]

- v1.01 - Adds support for B4i.

 

[omarruben]

wow!!!!!!!!! this is excellent !!!!! thank you!!!

 

[Martin Larsen]

Awesome. Could be very useful.

 

[Erel]

- v1.02 - Fixes an issue related to image vs. device orientation (https://www.b4x.com/android/forum/threads/hugeimageview-tile-not-showing-at-bottom.134387/).

 

[Erel]

V1.03 adds support for B4J. The B4J implementation is a bit different. It caches all tiles.

 

[alyami]

Thank you it was awesome, can we control level of zoom and center image by code?

 

[Erel]

Add this code to the class to center the image:

Public Sub CenterImage(ZoomLevel As Float)
    pnlBackground.SetLayoutAnimated(0, 0, 0, mBase.Width, mBase.Height)
    ZoomChanged(pnl.Width / 2, pnl.Height / 2, ZoomLevel)
End Sub

Pass 1 for no zoom.