resize

Usage

Scales up or down an image. You can adjust the image width and height by specifying the target size or scaling factor.

Multiple interpolation modes, such as cv2.INTER_LINEAR, cv2.INTER_CUBIC, and cv2.INTER_NEAREST_EXACT, are available to maintain the image quality during scaling.

Interface

cv2.resize(src, dsize, fx=0, fy=0, interpolation=cv2.INTER_LINEAR)

Parameters

Parameter	Description	Value Range	Input/Output
src	Input image.	Not null	Input
dsize	Size (width and height) of the target image. If this parameter is specified, the values of fx and fy are invalid. If this parameter is set to (0, 0) or not specified, the values of fx and fy are used.	Tuple (x, y), where x and y are positive integers	Input
fx	Horizontal scaling factor. The default value is 0.	(0, inf)	Input
fy	Vertical scaling factor. The default value is 0.	(0, inf)	Input
interpolation	Interpolation mode. The value can be cv2.INTER_LINEAR (default), cv2.INTER_NEAREST_EXACT, or cv2.INTER_CUBIC.	cv2.INTER_LINEAR (default), cv2.INTER_NEAREST_EXACT, cv2.INTER_CUBIC	Input

Return Values

Success: KP_CV_SUCCESS
Failure: an error code

Error Codes

Error Code	Description
INVALID_PARAM_MSG	The src parameter is null; the dsize value is incorrect; or the value of fx or fy is incorrect.
NOT_SUPPORT_MSG	The type of src is incorrect; the interpolation mode is not supported by interpolation; or the value of fx or fy is incorrect.

Example

import numpy as np
import cv2

# Create a 5x5 image.
src = np.array([[0, 0, 0, 0, 0],
               [0, 1, 1, 1, 0],
               [0, 1, 0, 1, 0],
               [0, 1, 1, 1, 0],
               [0, 0, 0, 0, 0]], dtype=np.uint8)  

dst = cv2.resize(src, dsize=(10, 10), interpolation=cv2.INTER_LINEAR)  

print(dst)

Output:

[[0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0]
 [0 0 1 1 1 1 1 1 0 0]
 [0 0 1 1 1 1 1 1 0 0]
 [0 0 1 1 0 0 1 1 0 0]
 [0 0 1 1 0 0 1 1 0 0]
 [0 0 1 1 1 1 1 1 0 0]
 [0 0 1 1 1 1 1 1 0 0]
 [0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0]]

Parent topic: Interface Definition