B4J Question Blurry ImageView after Rotation

[xulihang]

I am trying to rotate an ImageView with the following code:

Dim view As B4XView = ImageView2
view.Rotation = -10

But the image becomes blurry. Are there any ideas on how to solve this?

I've also attached a test project.

 

[teddybear]

Try this code

    ImageView2.As(JavaObject).RunMethod("setSmooth",Array(False))
    ImageView2.SetImage(Label1.Snapshot)
    Dim view As B4XView = ImageView2
    view.Rotation = -10

 

[xulihang]

It is still blurry.

    Dim jo As JavaObject = ImageView2
    jo.RunMethod("setSmooth",Array(False))
    ImageView1.SetImage(Label1.Snapshot)
    ImageView2.SetImage(Label1.Snapshot)
    Dim view As B4XView = ImageView2
    view.Rotation = -10

 

[xulihang]

I think it is inevitable that the text will become blurry after rotation because the image is resampled. The image has to be upscaled before rotation to solve the blurry problem.

 

[Brian Dean]

... because the image is resampled.

But also with a truly horizontal or vertical line the character edge can be a transition between "fully on" and "fully off" pixels. If you want sloped text lines then you either retain fully on/off pixels and create a "stepped" effect, or you use partially coloured (antialiased) pixels which is what I think you are describibg as "blurry". Surely sloped text will always be less sharp overall than horizontal text.

 

[Daestrum]

Got to be honest they don't look blurry to me after running your example. Maybe it's the display - at 4K they are just as sharp, rotated or not.

you could try (for imageview)

    Dim view As B4XView = ImageView2
    view.As(JavaObject).RunMethod("setSmooth",Array(False))
    view.Rotation = -15

to see if it improves the image

 

[xulihang]

Rotate the label and then take the snapshot instead of directly rotating the imageview. This seems to be the solution for me.

Dim lbl As B4XView = Label2
lbl.Rotation = -10
ImageView2.SetImage(Label2.Snapshot)