Structure of IMAGE MEMBLOCKS and a possible formula error.

Author

Message

P Schnell

20

Years of Service

User Offline

Joined: 13th Feb 2005

Location:

Posted: 10th Mar 2005 08:00

Link

+ Code Snippet

load bitmap "target.bmp",31

make memblock from bitmap 1,31

width=memblock dword(1,0)
height=memblock dword(1,4)

set current bitmap 0
print width," by ",height

pos=y*width+x
clr=memblock word(1,12+pos*2)
print rgbr(clr),",",rgbg(clr),",",rgbb(clr)

In the pos=y*width+x line x and y should be changed to the coordinate of a pixel, x=0-99 and y=0-49 because the image is 100x50.

It doesn't seem to get the right color, so I'm either thinking it's the structure of the memblock I've mistaken or the formula calculating which byte to start the word at.

This is the format of the memblock I've supposed:

BYTE 0-3 are the WIDTH
BYTE 4-7 are the HEIGHT
BYTE 8-11 are the DEPTH (I don't use this in calculating, should I?)

BYTE 12-13 are the first pixel, presumably coordinate 0,0.
BYTE 14-15 are the second pixel, presumably coordinate 1,0.
So-on until:
BYTE 202-203 is at 1,1 when the WIDTH of the image was 100.
And more until:
BYTE 2020-2021 is at 10,10.

With

+ Code Snippet

pos=y*width+x
clr=memblock word(1,12+pos*2)

Where x and y both equal 0, 0*width+0=0, so pos=0.
Then the position (12+0*2) would return a 12, presumably the first BYTE of the actual pixel data after the headers. So using MEMBLOCK WORD, I should get BYTES 12 and 13, which, if the pixel is pure red (255,0,0), I should have "255,0,0" returned when I call the RGBR and it's related functions.

Unfortunately, "0,248,0" is returned.

What went wrong there?

This is the bitmap I was using: (Saved as a PNG for posting, convert back to BMP to test it.)

The first 3 pixels are pure red, green, and blue respectively, and the last red dot is pure red at coordinates 10,10. The black is 0,0,0 and the grey is 128,128,128.

Thanks for any help.

Back to top

Profile PM

Jess T

Retired Moderator

21

Years of Service

User Offline

Joined: 20th Sep 2003

Location: Over There... Kablam!

Posted: 10th Mar 2005 17:09

Link

Your logic's right, from what I can see.

However, colour values are stored in DWords, and I think the order that the colours are stored in isn't actually RGB... I'm not sure what it is exactly, so you may want to experiment a little

Jess.

Team EOD :: Programmer/All-Round Nice Guy
Aust. Convention!

Back to top

Profile PM Email Website

P Schnell

20

Years of Service

User Offline

Joined: 13th Feb 2005

Location:

Posted: 11th Mar 2005 07:31 Edited at: 11th Mar 2005 07:38

Link

Isn't a DWORD 4 BYTES? 16 BIT bitmaps always have 2 BYTES per pixel, and the depth of the memblock when I called it was 16.

This is the read by BYTE of the first 100 BYTES in the memblock:

WIDTH
100 0 0 0

HEIGHT
50 0 0 0

DEPTH
16 0 0 0

PIXEL ONE
0 248

PIXEL TWO
227 7

PIXEL THREE
31 0

Then next pixels are black and are read as 0 0

All of the color formats in Photoshop 7 are 3 BYTES.

Back to top

Profile PM

Benjamin

22

Years of Service

User Offline

Joined: 24th Nov 2002

Location: France

Posted: 11th Mar 2005 07:57

Link

If your running at a 32bit desktop res then regardless of the image's depth I think when you convert it to a memblock it gets changed to 32bit anyway. In image memblocks, the format of image data is like this:

alpha, blue, green, red

The first pixel value in the memblock starts at byte 12, this is because the header is from 0 to 11 bytes which is right for a 12 byte header.

A while ago(months ago actually) I made a set of functions for dealing with memblock functions. Maybe they'll help you work out how image memblocks work:

FUNCTION MEM_setup(memblockNum,width,height,setType)
SELECT setType
CASE 1
	GLOBAL MEM_ATT_READ_MBN : MEM_ATT_READ_MBN = memblockNum
	GLOBAL MEM_ATT_READ_WIDTH : MEM_ATT_READ_WIDTH = width
	GLOBAL MEM_ATT_READ_HEIGHT : MEM_ATT_READ_HEIGHT = height
	ENDCASE
CASE 2
	GLOBAL MEM_ATT_WRITE_MBN : MEM_ATT_WRITE_MBN = memblockNum
	GLOBAL MEM_ATT_WRITE_WIDTH : MEM_ATT_WRITE_WIDTH = width
	GLOBAL MEM_ATT_WRITE_HEIGHT : MEM_ATT_WRITE_HEIGHT = height
	ENDCASE
ENDSELECT
ENDFUNCTION

FUNCTION MEM_dot(x,y,value)
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
ENDFUNCTION

FUNCTION MEM_dotRGB(x,y,red,green,blue)
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,blue
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,green
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,red
ENDFUNCTION

FUNCTION MEM_circle(xPos,yPos,size,value)
for xLoop=0 to 360
x=xPos+cos(xLoop)*size
y=yPos+sin(xLoop)*size
if x>0 and x=<MEM_ATT_WRITE_WIDTH-1 and y>0 and y=<MEM_ATT_WRITE_HEIGHT-1
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
endif
next xLoop
ENDFUNCTION

FUNCTION MEM_circlefilled(xPos,yPos,size,value)
size#=size
for x=xPos-(size/2) to xPos+(size/2)
for y=yPos-(size/2) to yPos+(size/2)
if sqrt((xPos-x)^2+(yPos-y)^2)*2<size#
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
if x>0 and x=<MEM_ATT_WRITE_WIDTH-1 and y>0 and y=<MEM_ATT_WRITE_HEIGHT-1
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
endif
endif
next y
next x
ENDFUNCTION

FUNCTION MEM_circle3(xPos,yPos,size,value,front)
size#=size
for x=xPos-(size/2) to xPos+(size/2)
for y=yPos-(size/2) to yPos+(size/2)
if sqrt((xPos-x)^2+(yPos-y)^2)*2<size#
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
if x>0 and x=<MEM_ATT_WRITE_WIDTH-1 and y>0 and y=<MEM_ATT_WRITE_HEIGHT-1 and MEM_point(x,y)<>front
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
endif
endif
next y
next x
ENDFUNCTION

FUNCTION MEM_dome(xPos,yPos,size,value)
size#=size
for x=xPos-(size/2) to xPos+(size/2)
for y=yPos-(size/2) to yPos
if sqrt((xPos-x)^2+(yPos-y)^2)*2<size#
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
if x>0 and x=<MEM_ATT_WRITE_WIDTH-1 and y>0 and y=<MEM_ATT_WRITE_HEIGHT-1
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
endif
endif
next y
next x
ENDFUNCTION

FUNCTION MEM_point(x,y)
memPos = (y*MEM_ATT_READ_WIDTH*4)+(x*4)
r = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+12)
g = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+13)
b = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+14)
value=rgb(b,g,r)
ENDFUNCTION value

FUNCTION MEM_pointRGB(x,y)
memPos = (y*MEM_ATT_READ_WIDTH*4)+(x*4)
MEM_POINTBLUE = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+12)
MEM_POINTGREEN = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+13)
MEM_POINTRED = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+14)
ENDFUNCTION

FUNCTION MEM_cls(memNum,value)
FILL MEMORY GET MEMBLOCK PTR(memNum)+12,value,GET MEMBLOCK SIZE(1)-12
ENDFUNCTION

FUNCTION MEM_copytoscreen(memNum)
LOCK PIXELS
ptrTo = GET PIXELS POINTER()
ptrFrom = GET MEMBLOCK PTR(memNum)+12
COPY MEMORY ptrTo,ptrFrom,GET MEMBLOCK SIZE(1)-12
UNLOCK PIXELS
ENDFUNCTION

+ Code Snippet

FUNCTION MEM_setup(memblockNum,width,height,setType)
SELECT setType
CASE 1
	GLOBAL MEM_ATT_READ_MBN : MEM_ATT_READ_MBN = memblockNum
	GLOBAL MEM_ATT_READ_WIDTH : MEM_ATT_READ_WIDTH = width
	GLOBAL MEM_ATT_READ_HEIGHT : MEM_ATT_READ_HEIGHT = height
	ENDCASE
CASE 2
	GLOBAL MEM_ATT_WRITE_MBN : MEM_ATT_WRITE_MBN = memblockNum
	GLOBAL MEM_ATT_WRITE_WIDTH : MEM_ATT_WRITE_WIDTH = width
	GLOBAL MEM_ATT_WRITE_HEIGHT : MEM_ATT_WRITE_HEIGHT = height
	ENDCASE
ENDSELECT
ENDFUNCTION

FUNCTION MEM_dot(x,y,value)
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
ENDFUNCTION

FUNCTION MEM_dotRGB(x,y,red,green,blue)
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,blue
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,green
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,red
ENDFUNCTION

FUNCTION MEM_circle(xPos,yPos,size,value)
for xLoop=0 to 360
x=xPos+cos(xLoop)*size
y=yPos+sin(xLoop)*size
if x>0 and x=<MEM_ATT_WRITE_WIDTH-1 and y>0 and y=<MEM_ATT_WRITE_HEIGHT-1
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
endif
next xLoop
ENDFUNCTION

FUNCTION MEM_circlefilled(xPos,yPos,size,value)
size#=size
for x=xPos-(size/2) to xPos+(size/2)
for y=yPos-(size/2) to yPos+(size/2)
if sqrt((xPos-x)^2+(yPos-y)^2)*2<size#
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
if x>0 and x=<MEM_ATT_WRITE_WIDTH-1 and y>0 and y=<MEM_ATT_WRITE_HEIGHT-1
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
endif
endif
next y
next x
ENDFUNCTION

FUNCTION MEM_circle3(xPos,yPos,size,value,front)
size#=size
for x=xPos-(size/2) to xPos+(size/2)
for y=yPos-(size/2) to yPos+(size/2)
if sqrt((xPos-x)^2+(yPos-y)^2)*2<size#
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
if x>0 and x=<MEM_ATT_WRITE_WIDTH-1 and y>0 and y=<MEM_ATT_WRITE_HEIGHT-1 and MEM_point(x,y)<>front
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
endif
endif
next y
next x
ENDFUNCTION

FUNCTION MEM_dome(xPos,yPos,size,value)
size#=size
for x=xPos-(size/2) to xPos+(size/2)
for y=yPos-(size/2) to yPos
if sqrt((xPos-x)^2+(yPos-y)^2)*2<size#
memPos = (y*MEM_ATT_WRITE_WIDTH*4)+(x*4)
if x>0 and x=<MEM_ATT_WRITE_WIDTH-1 and y>0 and y=<MEM_ATT_WRITE_HEIGHT-1
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+12,rgbb(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+13,rgbg(value)
WRITE MEMBLOCK BYTE MEM_ATT_WRITE_MBN,memPos+14,rgbr(value)
endif
endif
next y
next x
ENDFUNCTION

FUNCTION MEM_point(x,y)
memPos = (y*MEM_ATT_READ_WIDTH*4)+(x*4)
r = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+12)
g = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+13)
b = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+14)
value=rgb(b,g,r)
ENDFUNCTION value

FUNCTION MEM_pointRGB(x,y)
memPos = (y*MEM_ATT_READ_WIDTH*4)+(x*4)
MEM_POINTBLUE = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+12)
MEM_POINTGREEN = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+13)
MEM_POINTRED = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+14)
ENDFUNCTION

FUNCTION MEM_cls(memNum,value)
FILL MEMORY GET MEMBLOCK PTR(memNum)+12,value,GET MEMBLOCK SIZE(1)-12
ENDFUNCTION

FUNCTION MEM_copytoscreen(memNum)
LOCK PIXELS
ptrTo = GET PIXELS POINTER()
ptrFrom = GET MEMBLOCK PTR(memNum)+12
COPY MEMORY ptrTo,ptrFrom,GET MEMBLOCK SIZE(1)-12
UNLOCK PIXELS
ENDFUNCTION

"Lets migrate like bricks" - Me

Back to top

Profile PM Email

P Schnell

20

Years of Service

User Offline

Joined: 13th Feb 2005

Location:

Posted: 11th Mar 2005 08:04

Link

This is what I'm interested in:

FUNCTION MEM_pointRGB(x,y)
memPos = (y*MEM_ATT_READ_WIDTH*4)+(x*4)
MEM_POINTBLUE = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+12)
MEM_POINTGREEN = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+13)
MEM_POINTRED = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+14)
ENDFUNCTION

I'm wondering if you read it BYTE by BYTE, and the order is BGR? If so, where is the Alpha you mentioned earlier?

I'll play around with it when I get finished with my homework.

Back to top

Profile PM

Benjamin

22

Years of Service

User Offline

Joined: 24th Nov 2002

Location: France

Posted: 11th Mar 2005 08:12

Link

In my functions I left alpha out. If I were to include alpha it would probably be:

+ Code Snippet

FUNCTION MEM_pointRGB(x,y)
memPos = (y*MEM_ATT_READ_WIDTH*4)+(x*4)
MEM_POINTALPHA = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+11)
MEM_POINTBLUE = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+12)
MEM_POINTGREEN = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+13)
MEM_POINTRED = MEMBLOCK BYTE(MEM_ATT_READ_MBN,memPos+14)
ENDFUNCTION

Infact I may be wrong - alpha may be on the other side(+15) but I'm pretty sure I'm right.

"Lets migrate like bricks" - Me

Back to top

Profile PM Email

P Schnell

20

Years of Service

User Offline

Joined: 13th Feb 2005

Location:

Posted: 11th Mar 2005 08:20

Link

One more thing before I can test this: in the MEM_setup function, what is the SetType variable for, and what should I enter?

Back to top

Profile PM

Benjamin

22

Years of Service

User Offline

Joined: 24th Nov 2002

Location: France

Posted: 11th Mar 2005 08:25

Link

1 for reading, 2 for writing. Check the attached document for more information..

Really I should update those functions, theres some stuff going on there that doesn't need to go on.

"Lets migrate like bricks" - Me

Attachments

Login to view attachments

Back to top

Profile PM Email

P Schnell

20

Years of Service

User Offline

Joined: 13th Feb 2005

Location:

Posted: 11th Mar 2005 08:30 Edited at: 11th Mar 2005 08:31

Link

That wouldn't happen to be DBPro code, whould it? I'm getting an Unknown Command at either the "SELECT SetType" or "CASE 1."

They're both highlighted as a command in DarkEdit for Classic.

EDIT: Nevermind, it was the MEM_ATT_READ_MBN and related, where were those functions?

Back to top

Profile PM

Benjamin

22

Years of Service

User Offline

Joined: 24th Nov 2002

Location: France

Posted: 11th Mar 2005 08:37 Edited at: 11th Mar 2005 08:38

Link

Oopsy, it is DBP code. Nevermind...oh, and you can't do globals in DBC either can you.

The best way to do it would be like this:

+ Code Snippet

function mem_pointr(memNum,x,y)
width = memblock dword(memNum,0)
value = memblock byte(memNum,(y*width*4)+(x*4)+14)
endfunction value

function mem_pointg(memNum,x,y)
width = memblock dword(memNum,0)
value = memblock byte(memNum,(y*width*4)+(x*4)+13)
endfunction value

function mem_pointb(memNum,x,y)
width = memblock dword(memNum,0)
value = memblock byte(memNum,(y*width*4)+(x*4)+12)
endfunction value

function mem_pointa(memNum,x,y)
width = memblock dword(memNum,0)
value = memblock byte(memNum,(y*width*4)+(x*4)+11)
endfunction value

There, a set of functions to return various color values from a memblock specified in memNum.

"Lets migrate like bricks" - Me

Back to top

Profile PM Email

P Schnell

20

Years of Service

User Offline

Joined: 13th Feb 2005

Location:

Posted: 11th Mar 2005 08:47

Link

I'm still getting the wrong returns, am I using your functions correctly?

+ Code Snippet

load bitmap "target.bmp",31

make memblock from bitmap 1,31

set current bitmap 0

x=0
y=0
print mem_pointr(1,x,y),",",mem_pointg(1,x,y),",",mem_pointb(1,x,y)

end



function mem_pointr(memNum,x,y)
width = memblock dword(memNum,0)
value = memblock byte(memNum,(y*width*4)+(x*4)+14)
endfunction value

function mem_pointg(memNum,x,y)
width = memblock dword(memNum,0)
value = memblock byte(memNum,(y*width*4)+(x*4)+13)
endfunction value

function mem_pointb(memNum,x,y)
width = memblock dword(memNum,0)
value = memblock byte(memNum,(y*width*4)+(x*4)+12)
endfunction value

I'm getting 224,248,0 on a red pixel at 0,0.

Back to top

Profile PM

Benjamin

22

Years of Service

User Offline

Joined: 24th Nov 2002

Location: France

Posted: 11th Mar 2005 18:23

Link

Maybes its the desktop rsolution your using. Are you running in 32bit mode?

"Lets migrate like bricks" - Me

Back to top

Profile PM Email

blanky

20

Years of Service

User Offline

Joined: 3rd Aug 2004

Location: ./

Posted: 12th Mar 2005 01:51

Link

The DBPro image memblock format is different to the DBC one, I think.

Mr Blanky - This Time, It's Personal

Back to top

Profile PM Email Website

Benjamin

22

Years of Service

User Offline

Joined: 24th Nov 2002

Location: France

Posted: 12th Mar 2005 03:04 Edited at: 12th Mar 2005 03:06

Link

Er..come to think of it, DBC apps I think run in a 16bit res. Damn

Try changing to a 32bit res at the start of the program then try it.

"Lets migrate like bricks" - Me

Back to top

Profile PM Email

P Schnell

20

Years of Service

User Offline

Joined: 13th Feb 2005

Location:

Posted: 12th Mar 2005 06:31

Link

Yes, it works with 32 bit display. I'll post what I'm making once I finish.

Thanks!

Back to top

Profile PM

Benjamin

22

Years of Service

User Offline

Joined: 24th Nov 2002

Location: France

Posted: 12th Mar 2005 06:53

Link

Your welcome

"Lets migrate like bricks" - Me

Back to top

Profile PM Email

Sorry your browser is not supported!

DarkBASIC Discussion / Structure of IMAGE MEMBLOCKS and a possible formula error.

Attachments