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* Applied patch from theo (bug ID 16748) to enable JPEG scaling

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git-svn-id: trunk@15855 -
This commit is contained in:
michael 2010-08-19 17:08:43 +00:00
parent f939bb3848
commit dfe9701dc4
1 changed files with 34 additions and 7 deletions
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41
packages/fcl-image/src/fpreadjpeg.pas
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@ -48,6 +48,8 @@ type
TFPReaderJPEG = class(TFPCustomImageReader)
private
FSmoothing: boolean;
FMinHeight:integer;
FMinWidth:integer;
FWidth: Integer;
FHeight: Integer;
FGrayscale: boolean;
@ -69,6 +71,9 @@ type
property ProgressiveEncoding: boolean read FProgressiveEncoding;
property Smoothing: boolean read FSmoothing write SetSmoothing;
property Performance: TJPEGReadPerformance read FPerformance write SetPerformance;
property Scale: TJPEGScale read FScale write FScale;
property MinWidth:integer read FMinWidth write FMinWidth;
property MinHeight:integer read FMinHeight write FMinHeight;
end;
implementation
@ -177,28 +182,50 @@ var
end;
procedure InitReadingPixels;
var d1,d2:integer;
function DToScale(inp:integer):TJPEGScale;
begin
if inp>7 then Result:=jsEighth else
if inp>3 then Result:=jsQuarter else
if inp>1 then Result:=jsHalf else
Result:=jsFullSize;
end;
begin
FInfo.scale_num := 1;
FInfo.scale_denom := 1;// shl Byte(FScale);
if (FMinWidth>0) and (FMinHeight>0) then
if (FInfo.image_width>FMinWidth) or (FInfo.image_height>FMinHeight) then
begin
d1:=Round((FInfo.image_width / FMinWidth)-0.5);
d2:=Round((FInfo.image_height / FMinHeight)-0.5);
if d1>d2 then fScale:=DToScale(d2) else fScale:=DtoScale(d1);
end;
FInfo.scale_denom :=1 shl Byte(FScale); //1
FInfo.do_block_smoothing := FSmoothing;
if FGrayscale then FInfo.out_color_space := JCS_GRAYSCALE;
if (FInfo.out_color_space = JCS_GRAYSCALE) then begin
if (FInfo.out_color_space = JCS_GRAYSCALE) then
begin
FInfo.quantize_colors := True;
FInfo.desired_number_of_colors := 236;
end;
end;
if FPerformance = jpBestSpeed then begin
if FPerformance = jpBestSpeed then
begin
FInfo.dct_method := JDCT_IFAST;
FInfo.two_pass_quantize := False;
FInfo.dither_mode := JDITHER_ORDERED;
// FInfo.do_fancy_upsampling := False; can create an AV inside jpeglib
end;
end;
if FProgressiveEncoding then begin
if FProgressiveEncoding then
begin
FInfo.enable_2pass_quant := FInfo.two_pass_quantize;
FInfo.buffered_image := True;
end;
end;
end;
function CorrectCMYK(const C: TFPColor): TFPColor;