image to 2D-long-array

[Compact3]

I have an image in a picturebox loaded with bitblt. Now I want to get the region of a color in that image. So I thought, if I could get all the pixels in a 2D-long-array I could go through all of them to see wich pixels have the right color so I can make a region.

But, how can I get all the pixels into a 2D-pixel-array?
Or does someone know a faster way to get the region of a color?

[Oš kupit traktor]

I don't understand your problem but geting right pixels is something like this

Declare Function GetPixel Lib "gdi32.dll" ( _ 
	 ByVal hdc As Long, _ 
	 ByVal x As Long, _ 
	 ByVal y As Long) As Long 

dim Pixel(512,512) as long 'insted 512 set width and height of region
dim RightPixels(512,512) as boolean

sub GetRightPixels(color as long)
for i=1 to 512
for j=1 to 512
Pixel(i,j)=GetPixel(picture1.hdc,i,j) ' set scale to pixels in properties of your form and picturebox
if Pixel(i,j)=color then rightpixels(i,j)=True
next j
next i
end sub

[Compact3]

Hm...
Is that the fastest method? Cause I really need to have a fast method?
And if I have the right pixels? How can I make a region out of that?

[Oš kupit traktor]

Well there are faster, but more complicated, tehnicques:

First, declare functions and types

Private Type Bitmap
bmType As Long
bmWidth As Long
bmHeight As Long
bmWidthBytes As Long
bmPlanes As Integer
bmBitsPixel As Integer
bmBits As Long
End Type

dim rightpixels(0 to 512,0 to 512) as boolean  'instead 512 w-1 and h-1 :-)

Private Declare Function GetObject Lib "gdi32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, ByRef lpObject As Any) As Long

Private Declare Function GetBitmapBits Lib "gdi32" (ByVal hBitmap As Long, ByVal dwCount As Long, ByRef lpBits As Any) As Long

Private Declare Function SetBitmapBits Lib "gdi32" (ByVal hBitmap As Long, ByVal dwCount As Long, ByRef lpBits As Any) As Long

Now, you can get pixels more faster than with getpixel by this proc:

sub getrightpixels(color)

dim bm As bitmap
getobject picture1.image, len(bm), bm

dim pixeldata() as Byte 'byte beacuse you will get each of R,G, and B components

redim pixeldata(0 To (bm.bmBitsPixel \ 8) - 1, 0 To bm.bmWidth - 1, 0 To bm.bmHeight - 1) 'first dimension of array is 0=red, 1=green, 2=blue , second is x, and third is y

getbitmapbits picture1.image, bm.bmWidthBytes * bm.bmHeight, pixeldata(0, 0, 0) 'getting pixels

for i=0 to bm.bmWidth-1
for j=0 to bm.bmHeight-1
if RGB(pixeldata(0,i,j),pixeldata(1,i,j),pixeldata(2,i,j))=color then rightpixel(i,j)=true
next j
next i
end sub

I hope you understand this

About regions i don't know very much, but i will find out

[Compact3]

Yeah, I already knew about that procedure, but I have a slow computer. And it's for a game, to set up a world. And I want that to happen as fast as possible. So That's why I wanted to use a long-array instead of a byte-array cause long is faster than byte.


Maybe I should rephrase the question: "What's the fastest method to create a region of a color in a bitmap?"

[Oš kupit traktor]

There isn't any faster method than Getpixel in VB .

If you know C or C++, you can write an dll for faster, and long type data.

[Compact3]

No, I don't know C++.