lcPaint_ImageResize

This function performs resampling (or scaling, zooming) of a greyscale or RGB image to the desired destination width and height.
Resampling refers to changing the pixel dimensions (and therefore display size) of an image. When you downsample (or decrease the number of pixels), information is deleted from the image. When you upsample (or increase the number of pixels), new pixels are added based on color values of existing pixels. You specify an interpolation filter to determine how pixels are added or deleted.

BOOL lcPaint_ImageResize (
   HANDLE hImage,
   int NewWidth,
   int NewHeight,
   int Filter
);

Parameters

hImage

Handle to raster image object.

NewWidth

Destination image width (pixels)

NewHeight

Destination image height (pixels)

Filter

The following filters can be used as resampling filters:

Filter flag	Description
LC_IMGRES_BOX	Box, pulse, Fourier window, 1st order (constant) B-Spline
LC_IMGRES_BILINEAR	Bilinear filter
LC_IMGRES_BSPLINE	4th order (cubic) B-Spline
LC_IMGRES_BICUBIC	Mitchell and Netravali's two-param cubic filter
LC_IMGRES_CATMULLROM	Catmull-Rom spline, Overhauser spline
LC_IMGRES_LANCZOS3	Lanczos-windowed sinc filter

Return Value

If the function succeeds, the return value is nonzero (TRUE).

Code sample:

//-----------------------------------------------
void LcAppDemo01::LoadImages ()
{
  ...
  // copy image 11, then reduce resolution 4 times
  hImage2 = lcPaint_ImageAdd( 13 );
  lcPaint_ImageCopy( hImage, hImage2 );
  W = lcPropGetInt( hImage2, LC_PROP_IMAGE_W ) / 4;
  H = lcPropGetInt( hImage2, LC_PROP_IMAGE_H ) / 4;
  lcPaint_ImageResize( hImage2, W, H, LC_IMGRES_BICUBIC );
  ...
}