From: Vladislav Vinogradov <vlad.vinogradov@itseez.com>
Date: Fri, 27 Feb 2015 11:28:12 +0000 (+0300)
Subject: fix gpu HOG implementation:
X-Git-Tag: accepted/tizen/6.0/unified/20201030.111113~1314^2~180^2~20
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4539607ab100af875cb4ff7a66c22f3ac4989977;p=platform%2Fupstream%2Fopencv.git

fix gpu HOG implementation:

move hog::set_up_constants from constructor to compute method

if user changed CUDA device between constructor and computation,
some variables were uninitialized
(cherry picked from commit 21bbed7bafd25114ff15d8012f3f8619d258d0c1)
---

diff --git a/modules/gpu/src/hog.cpp b/modules/gpu/src/hog.cpp
index b7274d7..bff7caa 100644
--- a/modules/gpu/src/hog.cpp
+++ b/modules/gpu/src/hog.cpp
@@ -127,9 +127,6 @@ cv::gpu::HOGDescriptor::HOGDescriptor(Size win_size_, Size block_size_, Size blo
 
     Size cells_per_block = Size(block_size.width / cell_size.width, block_size.height / cell_size.height);
     CV_Assert(cells_per_block == Size(2, 2));
-
-    cv::Size blocks_per_win = numPartsWithin(win_size, block_size, block_stride);
-    hog::set_up_constants(nbins, block_stride.width, block_stride.height, blocks_per_win.width, blocks_per_win.height);
 }
 
 size_t cv::gpu::HOGDescriptor::getDescriptorSize() const
@@ -221,6 +218,9 @@ void cv::gpu::HOGDescriptor::computeGradient(const GpuMat& img, GpuMat& _grad, G
 
 void cv::gpu::HOGDescriptor::computeBlockHistograms(const GpuMat& img)
 {
+    cv::Size blocks_per_win = numPartsWithin(win_size, block_size, block_stride);
+    hog::set_up_constants(nbins, block_stride.width, block_stride.height, blocks_per_win.width, blocks_per_win.height);
+
     computeGradient(img, grad, qangle);
 
     size_t block_hist_size = getBlockHistogramSize();