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Vince's Corner Takeout
#10
Discrete cosine transform, interesting image processing algorithm -- WIP

Code: (Select All)
deflng a-z

const n = 10

type dct_type
        r as double
        g as double
        b as double
end type

type q_type
        r as _unsigned _byte
        g as _unsigned _byte
        b as _unsigned _byte
end type

dim shared pi as double
pi = _pi

img1 = _loadimage("greenland1.png", 32)

w = _width(img1)
h = _height(img1)

ww = (w\n+1)*n
hh = (h\n+1)*n

dim dct(ww, hh) as dct_type
dim q(ww, hh) as q_type

dim sr as double, sg as double, sb as double
dim c as double, cu as double, cv as double

img2 = _newimage(w, h, 32)
img3 = _newimage(w, h, 32)

img1_dct = _newimage(w, h, 32)
img2_dct = _newimage(w, h, 32)
img3_dct = _newimage(w, h, 32)

screen _newimage(3*w, 2*h, 32)
_putimage (0,0),img1

_source img1

'forward DCT
for y0=0 to hh-1 step n
for x0=0 to ww-1 step n
        for y=0 to n-1
        for x=0 to n-1
                sr = 0
                sg = 0
                sb = 0

                for v=0 to n-1
                for u=0 to n-1
                        if (x0 + u > w - 1) then px = x0 + u - n else px = x0 + u
                        if (y0 + v > h - 1) then py = y0 + v - n else py = y0 + v

                        z = point(px, py)
                        r = _red(z)
                        g = _green(z)
                        b = _blue(z)

                        c = cos((2*u + 1)*x*pi/(2*n)) * cos((2*v + 1)*y*pi/(2*n))

                        sr = sr + r*c
                        sg = sg + g*c
                        sb = sb + b*c
                next
                next

                if x = 0 then cu = 1/sqr(2) else cu = 1
                if y = 0 then cv = 1/sqr(2) else cv = 1

                dct(x0 + x, y0 + y).r = sr*cu*cv/(0.5*n)
                dct(x0 + x, y0 + y).g = sg*cu*cv/(0.5*n)
                dct(x0 + x, y0 + y).b = sb*cu*cv/(0.5*n)
        next
        next
next
next

'quantization
dim minr as double, ming as double, minb as double
dim maxr as double, maxg as double, maxb as double

minr = 1000000
ming = 1000000
minb = 1000000

maxr = -1000000
maxg = -1000000
maxb = -1000000

for y=0 to hh
for x=0 to ww
        if dct(x, y).r < minr then minr = dct(x, y).r
        if dct(x, y).g < ming then ming = dct(x, y).g
        if dct(x, y).b < minb then minb = dct(x, y).b

        if dct(x, y).r > maxr then maxr = dct(x, y).r
        if dct(x, y).g > maxg then maxg = dct(x, y).g
        if dct(x, y).b > maxb then maxb = dct(x, y).b
next
next

_dest img1_dct
for y=0 to hh
for x=0 to ww
        r = q(x, y).r
        g = q(x, y).g
        b = q(x, y).b

        pset (x, y), _rgb(r, g, b)
next
next


_dest img1_dct
for y=0 to hh
for x=0 to ww
        q(x, y).r = 255*(dct(x,y).r - minr)/(maxr - minr)
        q(x, y).g = 255*(dct(x,y).g - ming)/(maxg - ming)
        q(x, y).b = 255*(dct(x,y).b - minb)/(maxb - minb)

        r = q(x, y).r
        g = q(x, y).g
        b = q(x, y).b

        pset (x, y), _rgb(r, g, b)
next
next


_dest img2_dct
for y0=0 to hh-1 step n
for x0=0 to ww-1 step n
        for y=0 to 7 'n-1
        for x=0 to 7 'n-1
                r = q(x0 + x, y0 + y).r
                g = q(x0 + x, y0 + y).g
                b = q(x0 + x, y0 + y).b

                if (x0 + x < w) and (y0 + y < h) then pset (x0 + x, y0 + y), _rgb(r, g, b)
        next
        next
next
next

_dest img3_dct
for y0=0 to hh-1 step n
for x0=0 to ww-1 step n
        for y=0 to 2 'n-1
        for x=0 to 2 'n-1
                r = q(x0 + x, y0 + y).r
                g = q(x0 + x, y0 + y).g
                b = q(x0 + x, y0 + y).b

                if (x0 + x < w) and (y0 + y < h) then pset (x0 + x, y0 + y), _rgb(r, g, b)
        next
        next
next
next

_dest img2
'inverse DCT
for y0=0 to hh-1 step n
for x0=0 to ww-1 step n
        for y=0 to n-1
        for x=0 to n-1
                sr = 0
                sg = 0
                sb = 0

                for v=0 to 7 'n-1
                for u=0 to 7 'n-1
                        c = cos((2*x + 1)*u*pi/(2*n))*cos((2*y + 1)*v*pi/(2*n))

                        if u = 0 then cu = 1/sqr(2) else cu = 1
                        if v = 0 then cv = 1/sqr(2) else cv = 1

                        'sr = sr + dct(x + x3, y + y3).r*c*cu*cv
                        'sg = sg + dct(x + x3, y + y3).g*c*cu*cv
                        'sb = sb + dct(x + x3, y + y3).b*c*cu*cv

                        r = q(x0 + u, y0 + v).r
                        g =     q(x0 + u, y0 + v).g
                        b = q(x0 + u, y0 + v).b

                        sr = sr + c*cu*cv*((r/255)*(maxr - minr) + minr)
                        sg = sg + c*cu*cv*((g/255)*(maxg - ming) + ming)
                        sb = sb + c*cu*cv*((b/255)*(maxb - minb) + minb)
                next
                next

                sr = sr/(0.5*n)
                sg = sg/(0.5*n)
                sb = sb/(0.5*n)

                if (x0 + x < w) and (y0 + y < h) then pset (x0 + x, y0 + y), _rgb(sr, sg, sb)
        next
        next
next
next

_dest img3
'inverse DCT
for y0=0 to hh-1 step n
for x0=0 to ww-1 step n
        for y=0 to n-1
        for x=0 to n-1
                sr = 0
                sg = 0
                sb = 0

                for v=0 to 2
                for u=0 to 2
                        c = cos((2*x + 1)*u*pi/(2*n))*cos((2*y + 1)*v*pi/(2*n))

                        if u = 0 then cu = 1/sqr(2) else cu = 1
                        if v = 0 then cv = 1/sqr(2) else cv = 1

                        'sr = sr + dct(x + x3, y + y3).r*c*cu*cv
                        'sg = sg + dct(x + x3, y + y3).g*c*cu*cv
                        'sb = sb + dct(x + x3, y + y3).b*c*cu*cv

                        r = q(x0 + u, y0 + v).r
                        g = q(x0 + u, y0 + v).g
                        b = q(x0 + u, y0 + v).b

                        sr = sr + c*cu*cv*((r/255)*(maxr - minr) + minr)
                        sg = sg + c*cu*cv*((g/255)*(maxg - ming) + ming)
                        sb = sb + c*cu*cv*((b/255)*(maxb - minb) + minb)
                next
                next

                sr = sr/(0.5*n)
                sg = sg/(0.5*n)
                sb = sb/(0.5*n)

                if (x0 + x < w) and (y0 + y < h) then pset (x0 + x, y0 + y), _rgb(sr, sg, sb)
        next
        next
next
next


_dest 0
_putimage (w,0), img2
_putimage (2*w,0), img3
_putimage (0,h), img1_dct
_putimage (w,h), img2_dct
_putimage (2*w,h), img3_dct

do
loop until _keyhit=27
system
Reply


Messages In This Thread
Vince's Corner Takeout - by bplus - 04-29-2022, 02:12 PM
RE: Vince's Corner Takeout - by vince - 04-29-2022, 09:34 PM
RE: Vince's Corner Takeout - by vince - 05-02-2022, 03:10 AM
RE: Vince's Corner Takeout - by bplus - 05-02-2022, 04:25 AM
RE: Vince's Corner Takeout - by vince - 05-02-2022, 11:16 PM
RE: Vince's Corner Takeout - by vince - 05-03-2022, 01:10 AM
RE: Vince's Corner Takeout - by bplus - 05-03-2022, 01:15 AM
RE: Vince's Corner Takeout - by vince - 05-03-2022, 04:26 AM
RE: Vince's Corner Takeout - by bplus - 05-03-2022, 03:32 PM
RE: Vince's Corner Takeout - by vince - 05-10-2022, 03:41 AM
RE: Vince's Corner Takeout - by vince - 05-10-2022, 03:57 AM
RE: Vince's Corner Takeout - by dcromley - 05-10-2022, 02:57 PM
RE: Vince's Corner Takeout - by vince - 05-10-2022, 08:14 PM
RE: Vince's Corner Takeout - by SMcNeill - 05-10-2022, 02:59 PM
RE: Vince's Corner Takeout - by vince - 05-11-2022, 01:13 AM
RE: Vince's Corner Takeout - by dcromley - 05-11-2022, 01:58 AM
RE: Vince's Corner Takeout - by vince - 06-01-2022, 09:05 AM
RE: Vince's Corner Takeout - by vince - 08-11-2022, 02:51 AM
RE: Vince's Corner Takeout - by bplus - 06-03-2022, 02:47 PM
RE: Vince's Corner Takeout - by triggered - 06-04-2022, 02:00 AM
RE: Vince's Corner Takeout - by vince - 06-07-2022, 02:02 AM
RE: Vince's Corner Takeout - by bplus - 06-07-2022, 02:15 AM
RE: Vince's Corner Takeout - by vince - 07-13-2022, 05:23 AM
RE: Vince's Corner Takeout - by BSpinoza - 07-14-2022, 04:54 AM
RE: Vince's Corner Takeout - by bplus - 07-14-2022, 04:35 PM
RE: Vince's Corner Takeout - by aurel - 08-11-2022, 01:02 PM
RE: Vince's Corner Takeout - by bplus - 08-11-2022, 04:22 PM
RE: Vince's Corner Takeout - by aurel - 08-11-2022, 05:33 PM
RE: Vince's Corner Takeout - by BSpinoza - 08-12-2022, 03:44 AM
RE: Vince's Corner Takeout - by vince - 08-11-2022, 08:42 PM
RE: Vince's Corner Takeout - by vince - 08-19-2022, 05:00 AM
RE: Vince's Corner Takeout - by bplus - 08-19-2022, 06:33 PM
RE: Vince's Corner Takeout - by vince - 08-23-2022, 10:04 PM
RE: Vince's Corner Takeout - by vince - 11-04-2022, 01:48 AM
RE: Vince's Corner Takeout - by vince - 03-31-2023, 11:07 PM
RE: Vince's Corner Takeout - by vince - 09-18-2023, 11:45 PM
RE: Vince's Corner Takeout - by Dav - 09-19-2023, 12:54 AM
RE: Vince's Corner Takeout - by bplus - 09-19-2023, 01:37 AM
RE: Vince's Corner Takeout - by GareBear - 09-19-2023, 03:56 PM
RE: Vince's Corner Takeout - by bplus - 09-19-2023, 04:47 PM
RE: Vince's Corner Takeout - by vince - 09-19-2023, 06:54 PM
RE: Vince's Corner Takeout - by bplus - 09-19-2023, 09:02 PM
RE: Vince's Corner Takeout - by vince - 01-13-2024, 07:15 PM
RE: Vince's Corner Takeout - by bplus - 01-13-2024, 07:59 PM
RE: Vince's Corner Takeout - by GareBear - 01-13-2024, 10:54 PM
RE: Vince's Corner Takeout - by vince - 02-16-2024, 04:01 AM
RE: Vince's Corner Takeout - by bplus - 02-16-2024, 02:27 PM
RE: Vince's Corner Takeout - by vince - 02-16-2024, 07:16 PM
RE: Vince's Corner Takeout - by Sprezzo - 02-17-2024, 03:04 AM
RE: Vince's Corner Takeout - by bplus - 02-17-2024, 02:44 PM
RE: Vince's Corner Takeout - by vince - 10-07-2024, 08:11 AM
RE: Vince's Corner Takeout - by bplus - 10-07-2024, 01:32 PM
RE: Vince's Corner Takeout - by vince - 10-11-2024, 12:05 AM
RE: Vince's Corner Takeout - by vince - 10-11-2024, 12:16 AM
RE: Vince's Corner Takeout - by PhilOfPerth - 10-11-2024, 03:51 AM
RE: Vince's Corner Takeout - by vince - 10-11-2024, 07:55 PM
RE: Vince's Corner Takeout - by PhilOfPerth - 10-11-2024, 11:30 PM
RE: Vince's Corner Takeout - by vince - 10-15-2024, 10:54 AM
RE: Vince's Corner Takeout - by bplus - 10-15-2024, 01:40 PM



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