anembryonicpictureconverterforenterprise256cpixelmode.sdlbas

finp$="lena_80x200.png"
if argc>=3 then:finp$=command$(3):end if
'- original qbasic version - 0112141818
'- sdlbasic version - 0405111338
'- halftone picture converter (bmp 4/8/24bit)
xed=0:yed=0:open finp$ for input as #1:for i=1 to 16:n=readbyte(1):next:for i=1 to 2:n=readbyte(1):next
xed=readbyte(1)*256:xed=xed+readbyte(1):for i=1 to 2:n=readbyte(1):next:yed=readbyte(1)*256:yed=yed+readbyte(1)
close #1
setdisplay(xed,yed,32,1):paper(8^8-1):ink(0):pen(0):cls:
'- opens the image
loadimage(finp$,1):pasteicon(0,0,1)
dim clust[16,16] '-,o4b[2]
'-- define cluster

a$="00,09,02,11,04,13,06,15,08,01,10,03,12,05,14,07,"  '- 8x2 matrix

'a$="00,06,08,14,02,12,04,10,08,14,00,06,04,10,02,12"
for y2=0 to 7:for x2=0 to 1
  lc=(y2*2)+x2
  clust[x2,y2]=val(mid$(a$,(lc*3)+1,2)):next:next
dim cor[16]
cor[0]=0x000000:cor[1]=0x0000FF:cor[2]=0xFF0000:cor[3]=0xFF00FF
cor[4]=0x00FF00:cor[5]=0x00FFFF:cor[6]=0xFFFF00:cor[7]=0xFFFFFF
for y=0 to yed-1
  for x=0 to xed-1
    ind=point(x,y)

    b=ind mod 256:ind=int(ind/256)
    g=ind mod 256:ind=int(ind/256)
    r=ind mod 256

    b2=int(b/86)
    g2=int(g/37)
    r2=int(r/37)

    b3=int((b mod 86)*3)
    g3=int((g mod 37)*7)
    r3=int((r mod 37)*7)

    k=int(((b*11)+(r*30)+(g*59))/100)
    k2=int(((b2*11)+(r2*30)+(g2*59))/100)
    k3=int(((b3*11)+(r3*30)+(g3*59))/100)

    patgf=(((clust[x mod 2,y mod 8]+1)*255)/16)

    rpat=0:if r>patgf then:rpat=1:end if
    gpat=0:if g>patgf then:gpat=1:end if
    bpat=0:if b>patgf then:bpat=1:end if
    kpat=0:if k>patgf then:kpat=1:end if

    rpat2=0:if r2>patgf then:rpat2=1:end if
    gpat2=0:if g2>patgf then:gpat2=1:end if
    bpat2=0:if b2>patgf then:bpat2=1:end if
    kpat2=0:if k2>patgf then:kpat2=1:end if

    rpat3=0:if r3>patgf then:rpat3=1:end if
    gpat3=0:if g3>patgf then:gpat3=1:end if
    bpat3=0:if b3>patgf then:bpat3=1:end if
    kpat3=0:if k3>patgf then:kpat3=1:end if

    o4b=(bpat+(rpat*2)+(gpat*4)) mod 8
    'ink(0):if kpat<>0 then:ink(0xFFFFFF):end if
    'ink(cor[o4b])

    ink(rgb((r2+rpat3)*35,(g2+gpat3)*35,(b2+bpat3)*85))

    dot(x,y)
    next:next
'- saves the image
fout$=finp$+".bmp"
grab (1,0,0,xed,yed):saveimage(fout$,1)
shell ("convert "+finp$+".bmp "+finp$+".png")
shell ("rm "+finp$+".bmp")