[SOLVED] Splitting an image

[madref]

I have an image (TImage) that I want to split Ito two images so that I can put them under each other.
The Image is 365 pixel wide and I want to split into 165 and 200 pixels


How can I do that?

[paule32]

simply:
- use two separate TImage's like a map, or:
- use a tile map (a single file, with tiles in square with same width/height

good luck

[madref]

Can you explain it a bit more?
Because I don't understand what you mean

[paule32]

- you can use multiple images, that you can "TImage.LoadFromFile"
=> Then you have more loading time
=> Then you can store the images on Form's - but they overlapped eventually
=> Then you can exchange the images from each load time/update of your software
=> Then you can load/un-load the images which means, allocate/de-allocate memory

- you can use one or multiple tile images, load it per LoadFromFile, store it into a background Canvas/Handle, and BitBlt (copy) the background data into the foreground (enabled/viewing view port on TForm or other TComponent)
=> Then you can gzip/zlib (compress) these file/s to save storage space
=> Then you can copy in-Memory data into background Canvas/foreground Canvas in time faster than if you use TImage.LoadFromFile
=> Then you need a little bit lesser memory
=> Then you can hold one copy of the image in the memory
=> Eventually, you need more memory.

On tile images, you have to know the exact position of the tiles - when not, then you have eventually image garbage on the device where you display/print the image's/tile's.

[madref]

I don't need to save or do anything to the image.
I just want to split the image in two parts.
The image contains text (like "Text Example") that I want to split
And I want to display it as:


Text
Example

[paule32]

I don't write anything about "saving".

You maybe over read it:
the principle is:
- load a file (that can be done with "LoadFromFile")
- and BitBlt (copy a view port of the memory region of the image) to a destination Canvas

This Canvas can be any "displayable" device (screen, printer, or memory)

[TRon]

@madref:
1. Do you write the text yourself with code into the image ?
2. Are you sure you want to have two separate TImage components in return ? (resulting in a total of 3 TImage components on your form)
3. in case 2 applies do these two other TImage components already exist
4. in case answer to 2 is no then where do you want the resulting "splitted" images to be stored ?
5. Is the splitting process itself a manual step, e.g. you have to click a button or should it be done when something specific happens on the form ?

[madref]

the image is loaded like this from a TImageList. It is depended on a color:

Code: Pascal  [Select][+][-]

1.   case KleurPop of
2.     Oranje : ImageList_Divisie.GetBitmap(0,Image_Divisie.Picture.Bitmap); // Oranje
3.     Rood   : ImageList_Divisie.GetBitmap(1,Image_Divisie.Picture.Bitmap); // Rood
4.     Blauw  : ImageList_Divisie.GetBitmap(2,Image_Divisie.Picture.Bitmap); // Blauw
5.     Groen  : ImageList_Divisie.GetBitmap(3,Image_Divisie.Picture.Bitmap); // Groen
6.     Paars  : ImageList_Divisie.GetBitmap(4,Image_Divisie.Picture.Bitmap); // Paars
7.     Geel   : ImageList_Divisie.GetBitmap(5,Image_Divisie.Picture.Bitmap); // Geel
8.     Zwart  : ImageList_Divisie.GetBitmap(6,Image_Divisie.Picture.Bitmap); // Zwart
9.   end;  // case

the idea was to, if possible, split this image into 2 images. So the idea is to have 2 TImage placeholders
1 is holding the left part of the image and the other 1 is holding the right part of this image.
i have added an example image

[TRon]

the image is loaded like this from a TImageList. It is depended on a color:

That answers at least one of my questions .... 

Ah well, let's see how far you are able to get with the following (you would have to adjust to meet your specific requirements).

Code: Pascal  [Select][+][-]

1. procedure TForm1.Button1Click(Sender: TObject);
2. var
3.   sameArea: TRect;
4.   srcRect: TRect;
5.   dstRect: TRect;
6. begin
7.   // split original image into two separated ones
8.  
9.   // left part of original image has the exact same rectangle coordinates as
10.   // the destination image and is 165 pixels width.
11.   sameArea    := Bounds(0,0,165, Image1.Height);
12.   // Copy rectangle area from image1 (leftmost part) to image2
13.   Image2.Canvas.CopyRect(sameArea, Image1.Canvas, sameArea);
14.  
15.   // right part of original image is located 165 pixels from the left
16.   srcRect := Bounds(165, Image1.Canvas.ClipRect.Top, Image1.Canvas.ClipRect.Width-165, Image1.Canvas.ClipRect.Height);
17.   // copied image starts at topleft of canvas and is 200 pixels width
18.   dstRect := Bounds(  0,                          0,                              200, Image1.Canvas.ClipRect.Height);
19.   // copy rectangel from image1 (rightmost part) to image3
20.   Image3.Canvas.CopyRect(dstRect, Image1.Canvas, srcRect);
21. end;
22.  

[Dzandaa]

Hi,

You cant try this skeleton (using BGRABitmap)

B->

[madref]

@Dzandaa


You use

Code: Pascal  [Select][+][-]

1.                 Picture:= TBGRABitmap.Create;
2.                 Picture.LoadFromFile(DOpenPicture.FileName);
3.  

to load the picture.


But how do I do this from a TImageList

[Thaddy]

LoadFromStream/SaveToStream?

[Dzandaa]

Hi
@madref, there is a TBGRAImageList in the BGRABitmap distribution, but I didn't try it yet...

https://wiki.lazarus.freepascal.org/BGRAControls#TBGRAImageList

B->

[KodeZwerg]

Image2 will contain the left half and Image3 the right half from the original imagelist picture.

Code: Pascal  [Select][+][-]

1. procedure TForm1.Button1Click(Sender: TObject);
2. var
3.   LBMP: TBitmap;
4.   HalfBMP: TBitmap;
5.   X: Integer;
6. begin
7.   LBMP := TBitmap.Create;
8.   try
9.     HalfBMP := TBitmap.Create;
10.     try
11.       ImageList1.GetBitmap(0, LBMP); // here i do put the image from imagelist index 0 into LBMP
12.       X := LBMP.Width div 2; // at that position I do split the image
13.       HalfBMP.Width := X;
14.       HalfBMP.Height := LBMP.Height;
15.       // left half:
16.       HalfBMP.Canvas.CopyRect(Rect(0, 0, X, LBMP.Height), LBMP.Canvas, Rect(0, 0, X, LBMP.Height));
17.       Image2.Picture.Bitmap.Assign(HalfBMP);
18.       // right half:
19.       HalfBMP.Canvas.CopyRect(Rect(0, 0, X, LBMP.Height), LBMP.Canvas, Rect(X, 0, LBMP.Width, LBMP.Height));
20.       Image3.Picture.Bitmap.Assign(HalfBMP);
21.     finally
22.       HalfBMP.Free;
23.     end;
24.   finally
25.     LBMP.Free;
26.   end;
27. end;

[madref]

How to compensate for the black?
It should be transparent.