Questions tagged [tbitmap]

48 questions
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2 answers

Delphi - how do I crop a bitmap "in place"?

If I have a TBitmap and I want to obtain a cropped image from this bitmap, can I perform the cropping operation "in place"? e.g. if I have a bitmap that is 800x600, how can I reduce (crop) it so that it contains the 600x400 image at the centre, i.e.…
rossmcm
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8
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1 answer

In Delphi, how does TBitmap.Monochrome and .PixelFormat influcence the format of .ScanLine?

I want to assign a given buffer with a bitmap in Mono8 format (Monochrome 8 Bits) to a bitmap. I then assign the resulting bitmap to a TImage component to display it. The pictures are screenshots of the resulting display. The following code works…
dummzeuch
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6
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2 answers

Is it possible to smooth a scaled TBitmap in Delphi?

I am using Stretched=True on a TImage with a 256x256 bitmap. This gets scaled down by 1,2,4 or 8. As expected, text on the bitmap gets more horrible the more I depart from '1'. I notice though that Windows 7 explorer renders a scaled down version of…
Brian Frost
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4
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1 answer

Changes to TBitmap do not appear in rendered image in Delphi 6 DirectShow filter and generates lots of soft page faults

I have a Delphi6 DirectShow filter (push source video filter) written with the DSPACK component library. I am having a truly vexing problem with some simple code that modifies a bitmap before outputting the modified bitmap to the destination media…
Robert Oschler
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3
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1 answer

DIB to Tbitmap code manipulation to adapt PNG images?

I use this code to convert DIB to TBitmap, so how can i manipulate this code to be suitable to a PNG image (preseving its transparency)? I tired to set the Transparent property to true but it seems that the code was made for 256 color bitmap. code…
Sara S.
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3
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1 answer

TBitmap looses Clipping region after non-related graphics code

Please consider the following code: type TBaseControl = class(TWinControl) private FBitmap : TBitmap; public constructor Create(AOwner : TComponent); override; procedure DrawBorder; end; TForm1 = class(TForm) Button1:…
Blurry Sterk
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3
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2 answers

How can convert FMX.Graphics.TBitmap to VCL.Graphics.TBitmap or Vcl.Imaging.PngImage.TPngImage?

How a FMX.Graphics.TBitmap can be converted to VCL.Graphics.TBitmap or Vcl.Imaging.PngImage.TPngImage? I have both FMX form and VCL form in my project.
Loghman
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3
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1 answer

How to display a TBitmap with alpha channel on TImage correctly?

I have a TBitmap which contains semi-transparent image with alpha channel (in this example I got it from TPngImage). var SourceBitmap: TBitmap; PngImage: TPngImage; begin PngImage := TPngImage.Create(); SourceBitmap := TBitmap.Create(); …
Andrew
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3
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2 answers

TBitmap to TPngImage and Memory usage

I have an array of 11 white TBitmaps (32-bit 512x512 pixles = 1 MB) and I want to assign them to TPngImage array to reduce memory usage, I expect the 1 mb white bitmap to become 1.76 KB png and the memory usage drop dramatically I monitored that…
isa
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2
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1 answer

How to copy a gray-scale bitmap via ScanLine

I want to copy pixels from BMP1 to BMP2 but the copied image is gabbled. Why? Note: The input image is pf8bit; TYPE TPixArray = array[0..4095] of Byte; PPixArray = ^TPixArray; procedure Tfrm1.CopyImage; VAR BMP1, BMP2: TBitmap; y, x:…
Z80
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2
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1 answer

How to use DrawTransparentBitmap() in C++ Builder

Just trying to figure out how to use DrawTransparent in C++ Builder to draw a bitmap or tbitmap with an alpha channel so that the drawn image is semi-transparent with the background image. I looked all over the place and on this site but can't…
Jim
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1 answer

Access violation when freeing TBitmap variable -- Bitmap variable still assigned after freeing?

I have this code in a VCL Forms Application: implementation {$R *.dfm} var MyBitmap: TBitmap; procedure TFormMain.FormCreate(Sender: TObject); begin MyBitmap := TBitmap.Create; end; procedure TFormMain.FormDestroy(Sender: TObject); begin …
user1580348
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2
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1 answer

Delphi TBitmap to string via TBitmapSurface and back to TBitmap

I am doing following to convert TBitmap(Firemonkey) to string: function BitmapToBase64(Bitmap: Tbitmap): string; var BS: TBitmapSurface; AStream: TMemoryStream; begin BS := TBitmapSurface.Create; BS.Assign(Bitmap); BS.SetSize(300, 200); …
shariful
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2
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How to crop an FMX TBitmap

I receive a bitmap via TCameraComponent.SampleBufferReady event. Then I need to crop the received image so that I get a, for instance, recangular image. I calculate the necessary parameters in the following method: procedure…
asd-tm
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2
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Strange Delphi Android image assign / image garbled issue

I have some code that works fine in iOs, but which results in completely messed up images when on Android. I have found a partial workaround (not call some code), but it hints something is terrible wrong: // some bitmap object buffer for mainthread…
Tom
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