📄 imageascii.pas
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{------------------------------------------------------------------------------}
{ }
{ ImageAscii - Image to Ascii conversion }
{ Copyright(C) 2003 Kambiz R. Khojasteh, all rights reserved. }
{ }
{ kambiz@delphiarea.com }
{ http://www.delphiarea.com }
{ }
{ This unit is provided "AS IS" without any warranty of any kind, either }
{ express or implied. The entire risk as to the quality and performance }
{ of the functions provided in this unit are with you. The author is NOT }
{ liable for any DAMAGES resulting from the use and misuse of the unit, }
{ especially he is NOT liable for DAMAGES that were caused BY ANY VERSION }
{ WHICH HAS NOT BEEN PROGRAMMED BY THE AUTHOR HIMSELF. }
{ }
{ This Delphi unit is FREEWARE for non-COMMERCIAL use. If you want to }
{ change the source code in order to improve the features, performance, }
{ etc. please send to the author the new source code so that the author }
{ can have a look at it. The changed source code should contain }
{ descriptions what you have changed, and your name. The only thing you }
{ MAY NOT CHANGE is the original COPYRIGHT information. }
{ }
{------------------------------------------------------------------------------}
unit ImageAscii;
interface
uses
Windows, Classes, Graphics;
type
TConvertMode = (cmColor, cmGrayscale, cmMono);
procedure ImageToHTML(const FileName: String; out HTML: String;
const Map: String; Mode: TConvertMode; MaxRowWidth: Integer = 0;
Font: TFont = nil; const Head: String = ''; const Tail: String = '');
procedure GraphicToHTML(G: TGraphic; out HTML: String;
const Map: String; Mode: TConvertMode; MaxRowWidth: Integer = 0;
Font: TFont = nil; const Head: String = ''; const Tail: String = '');
implementation
uses
SysUtils;
const
FontColorTagBegin = '<FONT COLOR="#%2.2x%2.2x%2.2x">';
FontNameTagBegin = '<FONT NAME="%s" STYLE="font-size: %dpt">';
FontTagEnd = '</FONT>';
BoldTagBegin = '<B>';
BoldTagEnd = '</B>';
ItalicTagBegin = '<I>';
ItalicTagEnd = '</I>';
UnderlineTagBegin = '<U>';
UnderlineTagEnd = '</U>';
StrikeOutTagBegin = '<S>';
StrikeOutTagEnd = '<S>';
TeleTypeTagBegin = '<TT>';
TeleTypeTagEnd = '</TT>';
LineBreakTag = '<BR>';
SpecialSpace = ' ';
{ Helpper Functions }
// Calculate the propertionally shrinked size of the graphic
// according to the specified dimensions and text metrics.
procedure CalcShrinkedSize(G: TGraphic; MaxWidth, MaxHeight: Integer;
const tm: TTextMetric; out Width, Height: Integer);
begin
// Scale the image's width according to the text metrics
Width := MulDiv(G.Width, tm.tmHeight + tm.tmExternalLeading, tm.tmAveCharWidth);
Height := G.Height;
// if MaxWidth is zero, don't scale horizontally
if MaxWidth = 0 then MaxWidth := Width;
// if MaxHeight is zero, don't scale vertically
if MaxHeight = 0 then MaxHeight := Height;
// if image size is biger than max. dimensions, shrink it proportionally
if (Width > MaxWidth) or (Height > MaxHeight) then
begin
if (MaxWidth / Width) < (MaxHeight / Height) then
begin
Height := MulDiv(Height, MaxWidth, Width);
Width := MaxWidth;
end
else
begin
Width := MulDiv(Width, MaxHeight, Height);
Height := MaxHeight;
end;
end;
end;
// Returns the bitmap version of the given graphic object. The bitmap is
// proportionally scaled according to the specified dimensions and font's
// text metrics.
function GetBitmapOf(G: TGraphic; MaxWidth, MaxHeight: Integer; Font: TFont): TBitmap;
var
Width, Height: Integer;
TextMetric: TTextMetric;
begin
Result := TBitmap.Create;
try
// Get the text metrics of the font
if Font <> nil then Result.Canvas.Font.Assign(Font);
GetTextMetrics(Result.Canvas.Handle, TextMetric);
// Shrink the image size according to the max. dimensions and text metrics
CalcShrinkedSize(G, MaxWidth, MaxHeight, TextMetric, Width, Height);
// Draw the image on the bitmap
Result.Width := Width;
Result.Height := Height;
Result.Canvas.StretchDraw(Rect(0, 0, Width, Height), G);
except
// free the bitmap if any exception occured
Result.Free;
raise;
end;
end;
{ Global Procedures }
// Converts the given graphic object to ASCII image as HTML format
procedure GraphicToHTML(G: TGraphic; out HTML: String;
const Map: String; Mode: TConvertMode; MaxRowWidth: Integer;
Font: TFont; const Head, Tail: String);
var
Buffer: PChar;
Bitmap: TBitmap;
BitmapWidth: Integer;
BitmapHeight: Integer;
Colors: PRGBQuad;
LastColor: Integer;
Gray: Integer;
LastGray: Integer;
X, Y: Integer;
M: PChar;
// Formats the arguments and appends them to the buffer.
procedure AppendFormat(const Format: String; const Args: array of const);
begin
Inc(Buffer, FormatBuf(Buffer^, MaxInt, PChar(Format)^, Length(Format), Args));
end;
// Appends the text to the buffer.
procedure AppendText(const Text: String);
begin
Buffer := StrCopy(Buffer, PChar(Text)) + Length(Text);
end;
// Calculates the worst-case size of the buffer
function GetWorstCaseBufferSize: Integer;
var
PixelCount: Integer;
begin
PixelCount := BitmapWidth * BitmapHeight;
// Calculates the worst-case length of the HTML for saving pixels, and
// header and footer tags
Result := Length(Head) + Length(TeleTypeTagBegin)
+ BitmapHeight * Length(LineBreakTag)
+ Length(TeleTypeTagEnd) + Length(Tail);
if Mode = cmMono then
Inc(Result, PixelCount * Length(SpecialSpace) + (Length(FontColorTagBegin + FontTagEnd) - 8))
else
Inc(Result, PixelCount * Length(SpecialSpace) * (Length(FontColorTagBegin + FontTagEnd) - 8));
// Increases the calculated size by adding the space required to
// font related tags
if Font <> nil then
begin
Inc(Result, Length(FontNameTagBegin) + Length(Font.Name) + Length(FontTagEnd));
if fsBold in Font.Style then
Inc(Result, Length(BoldTagBegin) + Length(BoldTagEnd));
if fsItalic in Font.Style then
Inc(Result, Length(ItalicTagBegin) + Length(ItalicTagEnd));
if fsUnderline in Font.Style then
Inc(Result, Length(UnderlineTagBegin) + Length(UnderlineTagEnd));
if fsStrikeOut in Font.Style then
Inc(Result, Length(StrikeOutTagBegin) + Length(StrikeOutTagEnd));
end;
end;
begin
Bitmap := GetBitmapOf(G, MaxRowWidth, 0, Font);
try
// Save bitmap's dimensions for quick retrival
BitmapWidth := Bitmap.Width;
BitmapHeight := Bitmap.Height;
// Change bitmap format to high-color
Bitmap.PixelFormat := pf32bit;
// Reserve space for the HTML text
SetLength(HTML, GetWorstCaseBufferSize);
Buffer := PChar(HTML);
// Add HTML header tags
AppendText(Head);
AppendText(TeleTypeTagBegin);
// Add font related tags
if Font <> nil then
begin
AppendFormat(FontNameTagBegin, [Font.Name, Font.Size]);
if fsBold in Font.Style then
AppendText(BoldTagBegin);
if fsItalic in Font.Style then
AppendText(ItalicTagBegin);
if fsUnderline in Font.Style then
AppendText(UnderlineTagBegin);
if fsStrikeOut in Font.Style then
AppendText(StrikeOutTagBegin);
if Mode = cmMono then
AppendFormat(FontColorTagBegin, [GetRValue(Font.Color),
GetGValue(Font.Color), GetBValue(Font.Color)]);
end;
// Create the rest of HTML using the bitmap's pixels
M := PChar(Map);
LastColor := -1;
LastGray := -1;
for Y := 0 to BitmapHeight - 1 do
begin
Colors := Bitmap.ScanLine[Y];
// Start a new row by adding a line break
if Y <> 0 then
AppendText(LineBreakTag);
// Convert pixels in the current row
for X := 0 to BitmapWidth - 1 do
begin
if PInteger(Colors)^ <> LastColor then
begin
// Change the color
with Colors^ do
begin
if Mode = cmColor then
begin
// If there's any open font color tag, close it
if LastColor <> -1 then
AppendText(FontTagEnd);
// Add a new font color tag
AppendFormat(FontColorTagBegin, [rgbRed, rgbGreen, rgbBlue])
end
else
begin
Gray := (rgbRed * 30 + rgbGreen * 59 + rgbBlue * 11) div 100;
if Gray <> LastGray then
begin
if Mode = cmGrayscale then
begin
// If there's any open font color tag, close it
if LastGray <> -1 then
AppendText(FontTagEnd);
// Add a new font color tag
AppendFormat(FontColorTagBegin, [Gray, Gray, Gray])
end
else
M := PChar(Map) + (Length(Map) * Gray div 256);
LastGray := Gray;
end;
end;
end;
LastColor := PInteger(Colors)^;
end;
// Add a character for this pixel
if M^ <> ' ' then
begin
Buffer^ := M^;
Inc(Buffer);
end
else
AppendText(SpecialSpace);
// Move the pixel chanacter to the next one if the mode is not mono
if Mode <> cmMono then
begin
Inc(M);
if M^ = #0 then M := PChar(Map);
end;
// Move to the next pixel
Inc(Colors);
end;
end;
// If there's any open font color tag, close it
if (Mode <> cmMono) and (LastColor <> -1) then
AppendText(FontTagEnd);
// Close the open font related tags
if Font <> nil then
begin
if Mode = cmMono then
AppendText(FontTagEnd);
if fsStrikeOut in Font.Style then
AppendText(StrikeOutTagEnd);
if fsUnderline in Font.Style then
AppendText(UnderlineTagEnd);
if fsItalic in Font.Style then
AppendText(ItalicTagEnd);
if fsBold in Font.Style then
AppendText(BoldTagEnd);
AppendText(FontTagEnd);
end;
// Add the HTML fotter tags
AppendText(TeleTypeTagEnd);
AppendText(Tail);
// Set the size of the HTML text to actual size
SetLength(HTML, Buffer - PChar(HTML));
finally
Bitmap.Free;
end;
end;
// Converts the given imagefile to color/grayscale ASCII image as HTML format
procedure ImageToHTML(const FileName: String; out HTML: String;
const Map: String; Mode: TConvertMode; MaxRowWidth: Integer;
Font: TFont; const Head, Tail: String);
var
Picture: TPicture;
begin
Picture := TPicture.Create;
try
Picture.LoadFromFile(FileName);
GraphicToHTML(Picture.Graphic, HTML, Map, Mode, MaxRowWidth, Font, Head, Tail);
finally
Picture.Free;
end;
end;
end.
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