resize

This function resizes the image down to or up to the specified size.

cv2.resize(src, dsize[, dst[, fx[, fy[,interpolation]]]]) → dst

• src (np.ndarray): Input image. The image can have any number of channels, which are processed independently, but the depth should be cv2.CV_8U, cv2.CV_16U, cv2.CV_16S, cv2.CV_32F or cv2.CV_64F.
• dsize (tuple: (int, int)): output image size; if it equals zero, it is computed as dsize = Size(round(fx * src.cols), round(fy * src.rows)).
• dst (optional; np.ndarray): Output destination file.
• fx (optional; float): Scaling factor along horizontal axis. When set to 0, it is computed as (double)dsize.width/src.cols. Default is 0.
• fy (optional; float): Scaling factor along vertical axis. When set to 0, it is computed as (double)dsize.height/src.rows. Default is 0.
• interpolation (optional; cv2.INTER_*): Interpolation method. INTER_LINEAR is default. Choose from:
  • INTER_NEAREST
  • INTER_LINEAR
  • INTER_AREA
  • INTER_CUBIC
  • INTER_LANCZOS4

Resizing, by default, does only change the width and height of the image. The aspect ratio can be preserved or not, based on the requirement.

• Either dsize or both fx and fy must be non-zero.
• The initial dst type or size are not taken into account. Instead the size and type are derived from the src, dsize, fx, and fy.

• OpenCV Documentation