| T O P I C R E V I E W |
| yogiyang |
Posted - Jan 26 2019 : 07:14:26
Hello,
I have this code snippet in python which I have picked up from a script that is designed to run in GIMP and this script is working as documented in GIMP:
MyVal = (v-min) * 1.0/(max-min)
I have coded the same as follows in Delphi:
MyVal := Trunc((PixVal - Mini) * (1.0/(Maxi - Mini)));
But the code of Pascal always return zero (0)!
Here the values of PixVal = 122, Mini = 122, Max = 16712448
Any idea as to how to code this properly?
TIA
Yogi Yang |
| 2 L A T E S T R E P L I E S (Newest First) |
| yogiyang |
Posted - Jan 26 2019 : 07:51:07
Hello,
Here is the Pascal code that I have managed to convert from Python:
procedure GetMinMax(out PixMin, PixMax: Integer);
var
X, Y, PixClr: integer;
Clr: TRGB;
begin
PixMin := 1000;
PixMax := -1000;
for Y := 0 to ImageEnViewMain.IEBitmap.Height - 1 do
begin
for X := 0 to ImageEnViewMain.IEBitmap.Width - 1 do
begin
try
Clr := ImageEnViewMain.IEBitmap.Pixels[X, Y];
PixClr := TRGB2TColor(Clr);
if PixClr < PixMin then
PixMin := PixClr;
if PixClr > PixMax then
PixMax := PixClr;
except on E: Exception do
ShowMessage(e.Message);
end;
end;
end;
end;
function RemapPix(PixVal: Byte; Mini, Maxi: Integer): Integer;
var
FinalVal: Real;
begin
Result := Trunc((PixVal - Mini) * (1.0/(Maxi - Mini)));
end;
procedure GetRGB(const X, Y, Mini, Maxi: Integer; out R, G, B: Byte);
begin
R := ImageEnViewMain.IEBitmap.Pixels[X, Y].r;
G := ImageEnViewMain.IEBitmap.Pixels[X, Y].g;
B := ImageEnViewMain.IEBitmap.Pixels[X, Y].b;
R := RemapPix(R, Mini, Maxi);
G := RemapPix(G, Mini, Maxi);
B := RemapPix(B, Mini, Maxi);
end;
procedure ContrastStretch;
var
PixMin, PixMax: Integer;
X, Y, PixClr: integer;
R, G, B: Byte;
begin
GetMinMax(PixMin, PixMax);
for Y := 0 to ImageEnViewMain.IEBitmap.Height - 1 do
begin
for X := 0 to ImageEnViewMain.IEBitmap.Width - 1 do
begin
try
GetRGB(X, Y, PixMin, PixMax, R, G, B);
ImageEnViewMain.IEBitmap.Pixels[X, Y] := CreateRGB(R, G, B);
except on E: Exception do
ShowMessage(e.Message);
end;
end;
end;
ImageEnViewMain.Update;
end;
Yogi Yang |
| yogiyang |
Posted - Jan 26 2019 : 07:16:40
Hello,
The whole Python script is:
function get_min_max()
min, max = 1000, -1000
for y=0, height-1 do
for x=0, width-1 do
value = get_value(x,y)
if value<min then
min = value
end
if value>max then
max = value
end
end
end
return min,max
end
function remap(v, min, max)
return (v-min) * 1.0/(max-min)
end
function cs_get_rgb(x,y,min,max)
r,g,b = get_rgb(x,y)
r = remap(r, min, max)
g = remap(g, min, max)
b = remap(b, min, max)
return r,g,b
end
function contrast_stretch()
min, max = get_min_max()
for y=0, height do
for x=0, width do
set_rgb(x,y, cs_get_rgb(x,y,min,max))
end
end
flush ()
end
contrast_stretch()
Yogi Yang |
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