mt.opencv.warping

Affine-warping and cropping an image.

Functions

  • do_warp_image(): Takes an inverse warping transformation which goes from output image to input image and warps the input image.

  • warp_image(): Takes a warping transformation mapping input image coordinates to the unit square, scales it to the output resolution, then warps the input image.

  • crop_image(): Takes a crop window from input image and warp/resize it to output image.

mt.opencv.warping.do_warp_image(out_image: ndarray, in_image: ndarray, inv_tfm: Aff2d, inter_mode: str = 'nearest', border_mode: str = 'constant')

Takes an inverse warping transformation which goes from output image to input image and warps the input image.

Parameters:

  • out_image (numpy.ndarray) – output image to be warped and resized to

  • in_image (numpy.ndarray) – input image from which the warping takes place

  • inv_tfm (mt.geo.affine2d.Aff2d) – 2D transformation mapping pixel locations in the output image to pixel locations in the input image

  • inter_mode ({'nearest', 'bilinear'}) – interpolation mode. ‘nearest’ means nearest neighbour. ‘bilinear’ means bilinear interpolation

  • border_mode ({'constant', 'replicate'}) – border filling mode. ‘constant’ means filling zero constant. ‘replicate’ means replicating last pixels in each dimension.

mt.opencv.warping.warp_image(out_image: ndarray, in_image: ndarray, warp_tfm: Aff2d, inter_mode: str = 'nearest', border_mode: str = 'constant')

Takes a warping transformation mapping input image coordinates to the unit square, scales it to the output resolution, then warps the input image.

Parameters:

  • out_image (numpy.ndarray) – output image to be warped and resized to

  • in_image (numpy.ndarray) – input image from which the warping takes place

  • warp_tfm (mt.geo.affine2d.Aff2d) – 2D transformation mapping pixel locations in the input image to the [0,1]^2 square

  • inter_mode ({'nearest', 'bilinear'}) – interpolation mode. ‘nearest’ means nearest neighbour. ‘bilinear’ means bilinear interpolation

  • border_mode ({'constant', 'replicate'}) – border filling mode. ‘constant’ means filling zero constant. ‘replicate’ means replicating last pixels in each dimension.

mt.opencv.warping.crop_image(out_image: ndarray, in_image: ndarray, crop_rect: Rect, inter_mode: str = 'nearest', border_mode: str = 'constant')

Takes a crop window from input image and warp/resize it to output image.

Parameters:

  • out_image (numpy.ndarray) – output image to be cropped and resized to

  • in_image (numpy.ndarray) – input image from which the crop takes place

  • crop_rect (mt.geo.rect.Rect) – crop window

  • inter_mode ({'nearest', 'bilinear'}) – interpolation mode. ‘nearest’ means nearest neighbour interpolation. ‘bilinear’ means bilinear interpolation

  • border_mode ({'constant', 'replicate'}) – border filling mode. ‘constant’ means filling zero constant. ‘replicate’ means replicating last pixels in each dimension.