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KhronosGroup / OpenVX-api-docs

OpenVX API and extension specification documents
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HOGFeatures function #6

Open egorovp opened 5 years ago

egorovp commented 5 years ago

Problem

1) Why the third features' dimension aren't the same in CTS and in documentation? (therefore, the further formation of the output tensor is incorrect)

e.g. in CTS for the size of the third features' dimension it's not enough multiplication by (cells_per_block_w * cells_per_block_h) 2) In CTS TEST(HogFeatures, testNodeCreation): why bins_dims is passed instead of features' dimensions?

Links

1) Standard 2) Conformance Tests

fbrill3 commented 5 years ago

@egorovp, the best folks to look at these issues were on spring break last week, but will review them soon and get back to you.

fbrill3 commented 5 years ago

Here is some feedback on each of your two questions from one of our group members:

  1. Yes, the third dimension mentioned in the spec is not same as used in CTS. Need further check as to what is the correct way to implement or specify this and rectify spec/CTS.
  2. Looks like a bug in CTS. Need to check the sample implementation as well. HOG Feature descriptor dimension can be calculated by multiplying bins_dims by number of cells per block. For a square block and cell the number of cells per block will be either (block_width/cell_width)*2 or (block_height/cell_height)*2. Note that the spec states that the blocks are square grids and the third dimension specified in the equation gives the feature descriptor output size.
egorovp commented 5 years ago

@fbrill3, thank you for your responses. Looking forward to update