從圖像中選擇圖像部分？

Question

問候！

我有特殊的圖像：

憑藉其alghoritm我可以從這個圖像&選擇圖像部分在視覺上看出了我的currentry選擇？每個圖像部分由其他人用1個像素用特殊顏色（例如Fuchsia）分隔。

加入：

子圖象（或其中的任何）可以具有任何形式。

Answer 1

以下是查找圖像中子圖像的示例。

這個例子能夠找到凸形（矩形，三角形，圓形等）的任何子圖像。但它在凹形上不能正確工作。對於那些你需要修改算法，以便一旦你找到第一個像素，然後去掃描與flod填充類似算法的所有鄰居。

這裏是代碼：

unit Unit2; 

interface 

uses 
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics, 
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.ExtCtrls, Vcl.ComCtrls; 

type 
    TSubImage = record 
    LeftBound: Integer; 
    RightBound: Integer; 
    TopBound: Integer; 
    BottomBound: Integer; 
    end; 

    ASubImages = Array of TSubImage; 

    TForm2 = class(TForm) 
    Button1: TButton; 
    SourceImage: TImage; 
    ListView1: TListView; 
    SelectionImage: TImage; 
    procedure Button1Click(Sender: TObject); 
    procedure ListView1SelectItem(Sender: TObject; Item: TListItem; 
     Selected: Boolean); 
    procedure FormCreate(Sender: TObject); 
    procedure SelectionImageMouseMove(Sender: TObject; Shift: TShiftState; X, 
     Y: Integer); 
    private 
    { Private declarations } 
    public 
    { Public declarations } 
    end; 

var 
    Form2: TForm2; 
    SubImages: ASubImages; 

implementation 

{$R *.dfm} 

procedure FindSubimages(Bitmap: TBitmap; var Subimages: ASubImages); 
var X,Y,I: Integer; 
    //2D array we use to store to which image does which pixel belong 
    SubImagesMap: Array of Array of Integer; 
begin 
    //Set the map dimension to the same dimension of TBitmap we scan 
    SetLength(SubImagesMap,Bitmap.Width+1,Bitmap.Height+1); 
    for Y := 0 to Bitmap.Height-1 do 
    begin 
    for X := 0 to Bitmap.Width-1 do 
    begin 
     //Check to see if current pixel color is not of background color. 
     if Bitmap.Canvas.Pixels[X,Y] <> clFuchsia then 
     begin 
     //Check if we already moved rightward (current pixel X postion > 0) 
     if X > 0 then 
     begin 
      //Check if pixel to the left has already been assigned to a subimage number 
      //and assign current pixel to the same subimage number since they are adjenct 
      if SubImagesMap[X-1,Y] <> 0 then 
      begin 
      SubImagesMap[X,Y] := SubImagesMap[X-1,Y]; 

      //Here we are checking to see if current pixel is placed outside of subimage 
      //bonds and adjust them acordingly 
      //Check to se if pixel X position is leftwards to subimages left bound 
      if Subimages[SubImagesMap[X,Y]-1].LeftBound > X then 
       //Move subimage left bound to match pixel X position 
       Subimages[SubImagesMap[X,Y]-1].LeftBound := X; 
      //Check to se if pixel X position is rightwards to subimages right bound 
      if Subimages[SubImagesMap[X,Y]-1].RightBound < X then 
       //Move subimage right bound to match pixel X position 
       Subimages[SubImagesMap[X,Y]-1].RightBound := X; 
      //Check to se if pixel Y position is upwards to subimages top bound 
      if Subimages[SubImagesMap[X,Y]-1].TopBound > Y then 
       //Move subimage top bound to match pixel Y position 
       Subimages[SubImagesMap[X,Y]-1].TopBound := Y; 
      //Check to se if pixel Y position is downwards to subimages bottom bound 
      if Subimages[SubImagesMap[X,Y]-1].BottomBound < Y then 
       //Move subimage bottom bound to match pixel Y position 
       Subimages[SubImagesMap[X,Y]-1].BottomBound := Y; 
      end; 
     end; 
     //Check if we already moved downward (current pixel Y position > 0) 
     if Y > 0 then 
     begin 
      //Check if pixel above has already been assigned to a subimage number 
      //and assign current pixel to the same subimage number since they are adjenct 
      if SubImagesMap[X,Y-1] <> 0 then 
      begin 
      SubImagesMap[X,Y] := SubImagesMap[X,Y-1]; 

      //Here we are checking to see if current pixel is placed outside of subimage 
      //bonds and adjust them acordingly 
      //Check to se if pixel X position is leftwards to subimages left bound 
      if Subimages[SubImagesMap[X,Y]-1].LeftBound > X then 
       //Move subimage left bound to match pixel X position 
       Subimages[SubImagesMap[X,Y]-1].LeftBound := X; 
      //Check to se if pixel X position is rightwards to subimages right bound 
      if Subimages[SubImagesMap[X,Y]-1].RightBound < X then 
       //Move subimage right bound to match pixel X position 
       Subimages[SubImagesMap[X,Y]-1].RightBound := X; 
      //Check to se if pixel Y position is upwards to subimages top bound 
      if Subimages[SubImagesMap[X,Y]-1].TopBound > Y then 
       //Move subimage top bound to match pixel Y position 
       Subimages[SubImagesMap[X,Y]-1].TopBound := Y; 
      //Check to se if pixel Y position is downwards to subimages bottom bound 
      if Subimages[SubImagesMap[X,Y]-1].BottomBound < Y then 
       //Move subimage bottom bound to match pixel Y position 
       Subimages[SubImagesMap[X,Y]-1].BottomBound := Y; 
      end; 
     end; 
     //Check to see if current pixel has already been asigned a sibimage number 
     //I not we create a new subimage entry and assign its number to current pixel 
     if SubImagesMap[X,Y] = 0 then 
     begin 
      //Increase the size of dynamic array storing subimage records 
      SetLength(SubImages,Length(SubImages)+1); 

      //Assing current pixel the number of newly created subimage 
      SubImagesMap[X,Y] := Length(SubImages); 

      //Set subimage initial bounds which are coordinates of one pixel 
      //since we created new subimage for this pixel 
      SubImages[SubImagesMap[X,Y]-1].LeftBound := X; 
      SubImages[SubImagesMap[X,Y]-1].RightBound := X; 
      SubImages[SubImagesMap[X,Y]-1].TopBound := Y; 
      SubImages[SubImagesMap[X,Y]-1].BottomBound := Y; 
     end; 
     end; 
    end; 
    end; 
    //Reduce the size of SubImageMap array to free its memory 
    //Since SubImageMap is local array this is optional 
    SetLength(SubImagesMap,0,0); 
end; 

procedure TForm2.Button1Click(Sender: TObject); 
var I: Integer; 
    ListItem: TListItem; 
    ListColumn: TListColumn; 
begin 
    //Our procedure for finding subimages. It accepts two parameters 
    //First parameter is reference to TBitmap object containing original image 
    //Second is reference to variable in which subimage bouns will be stored to 
    FindSubimages(SourceImage.Picture.Bitmap, Subimages); 
    //Lets show our results in more readable format 
    //First we change the ListView style to vsReport so we can show our results 
    //in multiple columns 
    ListView1.ViewStyle := vsReport; 
    //Then we add necessary columns 
    ListColumn := ListView1.Columns.Add; 
    ListColumn.Caption := 'Subimage number'; 
    ListColumn.Width := 100; 
    ListColumn := ListView1.Columns.Add; 
    ListColumn.Caption := 'Left Bound'; 
    ListColumn.Width := 80; 
    ListColumn := ListView1.Columns.Add; 
    ListColumn.Caption := 'Right Bound'; 
    ListColumn.Width := 80; 
    ListColumn := ListView1.Columns.Add; 
    ListColumn.Caption := 'Top Bound'; 
    ListColumn.Width := 80; 
    ListColumn := ListView1.Columns.Add; 
    ListColumn.Caption := 'Bottom Bound'; 
    ListColumn.Width := 80; 
    //Iterate through all subimages and add data to ListView 
    for I := 0 to Length(Subimages)-1 do 
    begin 
    //Ad new item to list view 
    ListItem := ListView1.Items.Add; 
    //Use the reference of newly added item to set caption which will be the text 
    //in first column 
    ListItem.Caption := IntToStr(I+1); 
    //Add aditional subitems. Each of this subitems is shown in its own column 
    //NOTE: Make sure to have enough columns to show all subitems 
    //If you wanna field in certain column to be empty just pass an empty string '' 
    ListItem.SubItems.Add(IntToStr(SubImages[I].LeftBound)); 
    ListItem.SubItems.Add(IntToStr(SubImages[I].RightBound)); 
    ListItem.SubItems.Add(IntToStr(SubImages[I].TopBound)); 
    ListItem.SubItems.Add(IntToStr(SubImages[I].BottomBound)); 
    end; 
end; 

procedure TForm2.FormCreate(Sender: TObject); 
begin 
    //Make selection image 2 pixels larger so we will never draw right to the edge 
    //and therefore can easily use its defult transparency 
    SelectionImage.Width := SourceImage.Width+2; 
    SelectionImage.Height := SourceImage.Height+2; 
    //Shift selector image position one to the left and one up to be centered above 
    //SourceIMage. 
    SelectionImage.Left := SourceImage.Left-1; 
    SelectionImage.Top := SourceImage.Top-1; 
end; 

procedure TForm2.ListView1SelectItem(Sender: TObject; Item: TListItem; 
    Selected: Boolean); 
var Rect: TRect; 
begin 
    //Use SubImage bounds to form rectagnle we will use for our selection 
    Rect.Left := SubImages[Item.Index].LeftBound+1; 
    Rect.Right := SubImages[Item.Index].RightBound+2; 
    Rect.Top := SubImages[Item.Index].TopBound+1; 
    Rect.Bottom := SubImages[Item.Index].BottomBound+2; 
    //Clear previous selection 
    SelectionImage.Canvas.Brush.Color := clFuchsia; 
    SelectionImage.Canvas.FillRect(SelectionImage.Canvas.ClipRect); 
    //Draw new selection rectangle 
    SelectionImage.Canvas.Brush.Color := clLime; 
    SelectionImage.Canvas.FrameRect(Rect); 
end; 

procedure TForm2.SelectionImageMouseMove(Sender: TObject; Shift: TShiftState; X, 
    Y: Integer); 
begin 
    Form2.Caption := IntToStr(X); 
end; 

end. 

Answer 2

正如我所看到的，你有一個矩形的紫紅色的海洋，其中包含一些非紫紅色的島嶼。你想識別這些島嶼。一個簡單的算法如下：

1. 從圖像的一個角落開始，比如左上角。
2. 逐個像素地逐個處理圖像。所以，從左到右處理第一行，然後處理下一行，依此類推。
3. 當您找到一個非紫紅色的像素時，這是一個島的左上角。現在找到島上的其他地方。繼續沿着島的第一排行進，直到到達行的盡頭，或找到紫紅色的像素。現在你知道寬度。通過向下移動其中一列來查找高度，直到到達最下面一行，或找到紫紅色像素。
4. 現在您知道該島的左上角座標以及寬度和高度。用這些信息捕捉你需要的東西，並用紫紅色代替源圖像中的島狀矩形，以表明這些像素全部處理完畢。
5. 繼續從你剛捕獲的島嶼的右上角尋找下一個島嶼。
6. 當你到達圖像的右下方時，你已經確定了所有的島嶼。