Android Question GetPixel() too slow

[Fusseldieb]

Hi,
Is there a alternative method to GetPixel? Maybe with JavaObejct or something?
I already found a code here, but it throws an error everytime I try to read the Int value. (https://www.b4x.com/android/forum/threads/getpixels-from-a-bitmap.41999/#content)
I want to read an entire Canvas and then put the values in a loop to read those and do further processing...

Thanks for any help.

 

[stevel05]

To get help with this, please say what error you are getting and show the code that causes the error.

 

[Fusseldieb]

To get help with this, please say what error you are getting and show the code that causes the error.

Thanks for the reply.
I get that I cannot convert NumberToString.
How do I use that function in that link?
Is that an ItemArray, An Int or something else?
I do not understand how to get values from that code...
That's my question. Thanks ^^

@klaus may undestand it

 

[klaus]

The code you are refering to returns an array of Ints.
The function comes from HERE.

 

[Fusseldieb]

The code you are refering to returns an array of Ints.
The function comes from HERE.

But in B4A, how do I use it?

 

[DonManfred]

But in B4A, how do I use it?

Write a small java wrapper for this method or try to do it with javaobject or reflection

 

[klaus]

Attached you find a small example demonstrating getPixels and setPixels.
Clicking on the panel changes the color of the vertical line

 

[Fusseldieb]

Wow! Thank you. I understood the code now

 

[Fusseldieb]

The only thing I didn't understand is that:

        Log("-3 " & (pxlTest(pxlTest.Length - 3)))
    Log("-2 " & (pxlTest(pxlTest.Length - 2)))
    Log("-1 " & (pxlTest(pxlTest.Length - 1)))

What is this supposed to do?

pxlTest(1) gives me the first pixel... pxlTest(2) the second and so on, but I didn't understand pxlTest(pxlTest.Length - 1)

 

[klaus]

pxlTest(0) gives the first pixel ! Not pxlTest(1) !
pxlTest(pxlTest.Length - 1) gives the last pixel.
pxlTest(pxlTest.Length - 2) gives the last but one pixel.
etc.

 

[Fusseldieb]

pxlTest(pxlTest.Length - 1) gives the last pixel.
pxlTest(pxlTest.Length - 2) gives the last but one pixel.
etc.

But ".Length" is the Lenght of a string, not?
And with -1 you're cutting the last character from the string if I think right.

 

[klaus]

pxlTest is an Array of Ints (integers) not a String !
Length is the length, number of items, of the Array !
The count begins with 0 so the first item is pxlTest(0) and the last item is pxlTest(pxlTest.Length - 1).
If you Dim an Array like Dim MyVariable(200) As Int, the last item in the array is MyVariable(199) and not MyVariable(200).
MyVariable.Length = 200, but the last item is 199 so MyVariable.Length - 1.

 

[Fusseldieb]

Oh, thanks!!
Now I fully understand this
Thanks for your time