From 536506c3f49463f2a1ec9b5dc6497060ab8a5801 Mon Sep 17 00:00:00 2001
From: Megvii Engine Team <megengine@megvii.com>
Date: Fri, 23 Jul 2021 19:33:52 +0800
Subject: [PATCH] feat(functional): let interpolate support more modes

GitOrigin-RevId: 9693a1ac638658ca1ee0b5d0eff507d74fcc996d
---
 .../python/megengine/functional/vision.py     | 26 ++++++++++++++-----
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/imperative/python/megengine/functional/vision.py b/imperative/python/megengine/functional/vision.py
index 14044df1..60c1823f 100644
--- a/imperative/python/megengine/functional/vision.py
+++ b/imperative/python/megengine/functional/vision.py
@@ -17,7 +17,7 @@ from ..core.tensor.utils import astensor1d
 from ..tensor import Tensor
 from .elemwise import floor
 from .math import argsort
-from .tensor import broadcast_to, concat, expand_dims, reshape
+from .tensor import broadcast_to, concat, expand_dims, reshape, transpose
 
 
 def cvt_color(inp: Tensor, mode: str = ""):
@@ -474,7 +474,7 @@ def interpolate(
     :param size: size of the output tensor. Default: None
     :param scale_factor: scaling factor of the output tensor. Default: None
     :param mode: interpolation methods, acceptable values are:
-        "bilinear", "linear". Default: "bilinear"
+        "bilinear", "linear", "bicubic" and "nearest". Default: "bilinear"
     :param align_corners: This only has an effect when `mode`
         is "bilinear" or "linear". Geometrically, we consider the pixels of the input
         and output as squares rather than points. If set to ``True``, the input
@@ -511,8 +511,8 @@ def interpolate(
 
     """
     mode = mode.lower()
-    if mode not in ["bilinear", "linear"]:
-        raise ValueError("interpolate only support linear or bilinear mode")
+    if mode not in ["bilinear", "linear", "bicubic", "nearest"]:
+        raise ValueError("unsupported interpolate mode: {}".format(mode))
     if mode not in ["bilinear", "linear"]:
         if align_corners is not None:
             raise ValueError(
@@ -625,9 +625,21 @@ def interpolate(
         weight = broadcast_to(weight, (inp.shape[0], 3, 3))
 
     weight = weight.astype("float32")
-    ret = warp_perspective(inp, weight, dsize, interp_mode="linear")
-    if mode == "linear":
-        ret = reshape(ret, ret.shape[0:3])
+    if mode in ["linear", "bilinear"]:
+        ret = warp_perspective(inp, weight, dsize, interp_mode="linear")
+        if mode == "linear":
+            ret = reshape(ret, ret.shape[0:3])
+    else:
+        # only NHWC format support "cubic" and "nearest" mode
+        inp = transpose(inp, (0, 2, 3, 1))
+        ret = warp_perspective(
+            inp,
+            weight,
+            dsize,
+            format="NHWC",
+            interp_mode="cubic" if mode == "bicubic" else mode,
+        )
+        ret = transpose(ret, (0, 3, 1, 2))
     return ret
 
 
-- 
GitLab