Why isn't this working?

Blitz3D Forums/Blitz3D Beginners Area/Why isn't this working?

Galdy

(Posted 2011) [#1]

This should turn every pixel with a green value between 44 and 250 to
0,255,0. However, when i check it with my paint program it has missed some pixels that fall within that range I set. ??

For x=0 To ImageWidth(Image60)
For y=0 To ImageHeight(Image60)
GetColor x,y
If ColorGreen()>44 And ColorGreen()<250 Then
Color 0,255,0
Plot x,y
EndIf
Next
Next

Galdy

(Posted 2011) [#2]

Actualy this isn't changing any pixels. I just compared the result with the original. hmm

Galdy

(Posted 2011) [#3]

For goodness sakes. I need to Grabimage so i can save the results. LOL.

Kryzon

(Posted 2011) [#4]

Are you grabbing AND setting values from the image's buffer?

SetBuffer ImageBuffer(Image60)
For X = 0 to ImageWidth(Image60)-1 ;Pixel coordinates are zero-based, so that's why the "-1".
	For Y = 0 To ImageHeight(Image60)-1
		GetColor X,Y
		If ColorGreen() > 44 And ColorGreen() < 250 Then
			Color 0,255,0
			Plot X,Y
		EndIf
	Next
Next

See if this works.
(make sure to use the CODE tags to preserve indentation).

Matty

(Posted 2011) [#5]

and a faster way of doing this using the information supplied

lockbuffer imagebuffer(image60)
for x = 0 to imagewidth(image60) - 1
	for y = 0 to imageheight(image60) - 1
		rgb=readpixelfast(x,y,imagebuffer(image60))
		green = (rgb shr 8) and 255
		if green > 44 and green < 250 then 
			red = (rgb shr 16) and 255
			blue = (rgb and 255)
			writepixelfast(x,y,(red shl 16) or (255 shl 8) or blue,imagebuffer(image60)
		endif 
	next
next

unlockbuffer imagebuffer(image60)

Galdy

(Posted 2011) [#6]

Thanks for the input guys. All is well.