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AndyColmes
USA
351 Posts |
 Posted - Oct 04 2018 : 16:29:33
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I have this function but it uses TBitmap. I tried changing it to TIEBitmap but it gives an error in the Palette:
procedure SetBitmap8bitPalette(const Palette: T8bitPaletteArray; Bitmap: TBitmap);
// Add a 256-color palette to a bitmap
var
i, y: integer;
pal: PLogPalette;
hpal: HPALETTE;
begin
if not assigned(Bitmap) then exit;
// 8 bits per pixel
Bitmap.PixelFormat := pf8bit;
// Create a gradient palette between foreground and background color
GetMem(pal, sizeof(TLogPalette) + sizeof(TPaletteEntry) * 256);
try
pal.palVersion := $300;
pal.palNumEntries := 256;
for i := 0 to 255 do begin
pal.palPalEntry[i].peRed := Palette[i].R;
pal.palPalEntry[i].peGreen := Palette[i].G;
pal.palPalEntry[i].peBlue := Palette[i].B;
end;
hpal := CreatePalette(pal^);
if hpal <> 0 then
Bitmap.Palette := hpal; <--- Error!
finally
FreeMem(pal);
end;
// Fill bitmap with background color
for y := 0 to Bitmap.Height - 1 do
FillChar(Bitmap.Scanline[y]^, Bitmap.Width, 0);
end;
I appreciate any help you can offer. Thank you in advance.
Andy
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xequte
39053 Posts |
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AndyColmes
USA
351 Posts |
Posted - Oct 04 2018 : 23:13:24
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Hi Nigel,
Thanks for the info. What would be the values to use the ConvertTo function to do what the SetBitmap8bitPalette does?
Thanks again.
Andy
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AndyColmes
USA
351 Posts |
Posted - Oct 04 2018 : 23:40:07
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| Right now, I have to create a TBitmap, run SetBitmap8bitPalette on it and then assign it to a TIEBitmap which I think increases overhead and gives "not enough storage" memory error when dealing with large images |
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xequte
39053 Posts |
Posted - Oct 05 2018 : 00:30:35
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Hi Andy
The third overload accepts Palette as an array of TRGB:
function ConvertTo(PixelFormat: TIEPixelFormat; Palette: array of TRGB; DitherType: TIEDitherType = iedtSolid; CheckParametersOnly: boolean = false): boolean; overload;
So you can assign your TBitmap to a TIEBitmap, convert your T8bitPaletteArray to an array of TRGB then call:
ImageEnView1.Proc.ConvertTo(ie8p, MYPALETTE, iedtErrorDiffusion);
ImageEnView1.IO.Params.BitsPerSample := 8;
ImageEnView1.IO.Params.SamplesPerPixel := 1;
If you just want a general 256 color palette, use:
ImageEnView1.Proc.ConvertTo(256);
Nigel
Xequte Software
www.imageen.com
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How to convert function to use TIEBitmap
