Declaration
function JoinBitmaps(Source1, Source2: TIEBitmap; JoinVertically: Boolean; BGColor: TColor = clWhite; StripOverlap: Boolean = False; MinEquality: Double = 0.99; Coverage: Double = 1.0): Integer;
Description
Replaces the content with two source images drawn side-by-side (or above and below if
JoinVertically=True).
Both bitmaps must be ie24RGB.
If StripOverlap = True, then the result is the number of rows/colums that were cropped (if the result is 0 then no overlap could be found).
| Parameter | Description |
| Source1, Source2 | Specifies the two source images (either can be nil to specify this bitmap) |
| JoinVertically | If False, Source1 is drawn on the left and Source 2 on the right. If True, Source1 is drawn on the top and Source 2 on the bottom |
| BGColor | If one image is taller/wider than the other there will be background showing. Specify the color of the background fill, or clNone to fill with alpha |
| StripOverlap | If enabled, a check is performed to see if there is any overlapping pixels on the joining edge of the two images (Using CompareWith), and it is removed |
| MinEquality | If StripOverlap = True, this specifies the level of equality to look for when comparing the overlapping region (from 0.0 to 1.0, where 1.0 looks for an exact match) |
| Coverage | If StripOverlap = True, this specifies how extensively we check for overlap matching. This is used to speed up processing of very large images. For example, 1.0 means we check every row, 0.1 means we only check every tenth row, etc. |
Notes:
- You may specify the current bitmap for Source1 or Source2
- if StripOverlap = True it looks for overlap at a maximum of 50% of the width/height of the smallest image
TIEBitmap Assignment and Drawing Methods
TIEBitmap Methods | Method | Mode | Notes |
| Assign | From TIEBitmap/TBitmap/TGraphic/TIcon | Copy whole image |
| AssignImage | From TIEBitmap | Like assign, but does not copy the alpha channel |
| AssignRect | From TIEBitmap/TBitmap | Copy a specified rect |
| CopyAndConvertFormat | From TIEBitmap | Copy whole image |
| CopyRectTo | To TIEBitmap | Copy rect to another image (without scaling) |
| CopyWithMask1 | To TIEBitmap | Copy image using a mask to specify what is copied from the source |
| CopyWithMask2 | To TIEBitmap | Copy image using a mask to specify what is replaced in the destintation |
| DrawToTIEBitmap | To TIEBitmap | Copies all or part of the image to a specified position and/or size |
| JoinBitmaps | From two TIEBitmaps | Draws two bitmaps to a single bitmaps |
| MergeAlphaRectTo | With TIEBitmap | Merges all or part of two TIEBitmaps with alpha channels to a specified position using merge rules |
| MergeWithAlpha | With TIEBitmap | Merges all or part of two TIEBitmaps with alpha channels to a specified position |
| RenderToTIEBitmapEx | To TIEBitmap | Extended drawing of content to a TIEBitmap |
| StretchRectTo | To TIEBitmap | Copy rect to dest rect in another image (with scaling) |
| SwitchTo | To TIEBitmap | Move content from one TIEBitmap to another |
Examples
// Draw an image on the right of the current image (blank space will be transparent)
bmp := TIEBitmap.Create();
bmp.Read( 'D:\image2.png' );
ImageEnView1.IEBitmap.JoinBitmaps( nil, bmp, False, clNone );
bmp.Free;
ImageEnView1.Update();
// Create a PDF document with two stacked landscape images
bmp1 := TIEBitmap.Create();
bmp2 := TIEBitmap.Create();
destBmp := TIEBitmap.Create();
bmp1.Read( 'D:\im1.jpg' );
bmp2.Read( 'D:\im2.jpg' );
destBmp.JoinBitmaps( bmp1, bmp2, True, clWhite );
destBmp.RemoveAlphaChannel( True ); // Discard any alpha channel if not needed to reduce file size
destBmp.ParamsEnabled := True;
destBmp.Params.PDF_PaperSize := iepA4;
destBmp.Params.PDF_Compression := ioPDF_JPEG;
destBmp.Params.JPEG_Quality := 90;
destBmp.Write('D:\out.pdf');
bmp1.Free();
bmp2.Free();
destBmp.Free();
// Duplicate the bitmap verticaly
bmp.JoinBitmaps( bmp, bmp, True );
// Join two images removing any part of the image that is the same at the joining edge
// Exact matches only. Don't use exact matches for lossy formats like JPEG
ImageEnView3.IEBitmap.JoinBitmaps( ImageEnView1.IEBitmap, ImageEnView2.IEBitmap, False, clWhite, True, 1.0 );
// Quick joining of two images removing any part of the image that is the same at the joining edge
// This method only checks every 100th row so overlap detection may not be as accurate, but it is much faster
ImageEnView3.IEBitmap.JoinBitmaps( ImageEnView1.IEBitmap, ImageEnView2.IEBitmap, False, clWhite, True, 0.98, 0.01 );
// Horizontally join 5 images that have overlapping joining edges
bmpIn := TIEBitmap.Create();
bmpOut := TIEBitmap.Create();
for i := 1 to 5 do
begin
bmpIn.Read( 'D:\Join' + i.ToString + '.jpg' );
if i = 1 then
bmpOut.Assign( bmpIn )
else
bmpOut.JoinBitmaps( nil, bmpIn, False, clWhite, True, 0.997 );
end;
// Show result
ImageEnView1.Assign( bmpOut );
bmpIn .Free;
bmpOut.Free;