TImageEnView.Select

Declaration

procedure Select(x1, y1, x2, y2: integer; Op: TIESelOp = iespReplace); overload;
procedure Select(R: TRect; Op: TIESelOp = iespReplace); overload;

Description

Selects a portion of the image.
The selected area will be outlined with an animated rectangle.
If SelectionBase is iesbClientArea (default) all coordinates depend on actual zoom and scrolling.
If SelectionBase is iesbBitmap, all coordinates refer to bitmap pixels.

Parameter	Description
x1	Top-left horizontal position
y1	Top-left vertical position
x2	Bottom-right horizontal position. Last column not selected
y2	Bottom-right vertical position. Last row not selected
Op	Selection operation (add or replace selection). If Op is iespReplace, Select replaces all previous selections. If Op is iespAdd, Select adds a new selection

The style of selection are specified by:
◼SelColor1
◼SelColor2
◼SetSelectionGripStyle

Note
x2, y2 represent the right/bottom margin (i.e. those pixels are not selected).

ImageEnView1.SelectionBase := iesbBitmap;
ImageEnView1.Select( 100, 100, 200, 200 );
Caption := format(' %d,%d,%d,%d', [ ImageEnView1.SelX1, ImageEnView1.SelY1, ImageEnView1.SelX2, ImageEnView1.SelY2 ]);
// Caption will be: 100,100,199,199

To select an area of 1x1 pixels, you would use 0,0,1,1 (as the column 1 and the row 1 aren't selected).

Examples

// Increase contrast of bitmap rectangle (0,0,49,49)
ImageEnView1.SelectionBase := iesbBitmap;
ImageEnView1.Select(0, 0, 50, 50);
ImageEnView1.Proc.Contrast(10);
ImageEnView1.Deselect();

// Enlarge the selection by ten pixels on all sides
ImageEnView1.SelectionBase := iesbBitmap;
ImageEnView1.Select( ImageEnView1.SelX1 - 10, ImageEnView1.SelY1 - 10, ImageEnView1.SelX2 - 10, ImageEnView1.SelY2 - 10 );

// Test if the image is blank (with 1% threshold and ignoring the border area)
threshold := 1.0; // Allow 1% of image to be a different color
borderPerc := 10;   // Border area is 10% of width/height
ImageEnView1.SelectionBase := iesbBitmap;
ImageEnView1.Select( MulDiv( ImageEnView1.IEBitmap.Width, borderPerc, 100 ),
                     MulDiv( ImageEnView1.IEBitmap.Height, borderPerc, 100 ),
                     MulDiv( ImageEnView1.IEBitmap.Width, 100 - borderPerc, 100 ),
                     MulDiv( ImageEnView1.IEBitmap.Height, 100 - borderPerc, 100 ));
if ImageEnView1.Proc.GetDominantColor(cl) >= 100 - threshold then
  ShowMessage('Image is blank!')
else
  ShowMessage('Image is NOT blank!');
ImageEnView1.Deselect();

// Select whole image and allow user to deselect circular regions
With ImageEnView1 do
begin
  SelectionBase := iesbBitmap;
  Select( 0, 0, IEBitmap.Width, IEBitmap.Height );
  ShiftKeyLock := [ iessCtrl_SubFromSel ];
  MouseInteractGeneral := [ miSelectCircle ];
end;

// Subtract a circular area from a rectangular selection
ImageEnView1.Select( 42, 133, 326, 214, iespReplace );
ImageEnView1.SelectEllipse( 145, 130, 155, 170, iespSubtract );

// Apply negative effect at 50% intensiry
ImageEnView1.SelectionMaskDepth := 8;
ImageEnView1.SelectionIntensity := 128; // 128=50% selected
ImageEnView1.Select( 10, 10, 100, 100 );
ImageEnView1.Proc.Negative();

Other Selection Methods

◼SelectEllipse
◼SelectMagicWand
◼SelectChromaKey
◼SelectRoundRect
◼SelectShape

TImageEnView.Select