Determining custom Yolov4 output layer shape for 2 classes - ml.net

I've recently trained a darknet yolov4 model to detect 2 objects, converted it to tensorflow and then onnx using the following tutorial.
https://github.com/onnx/models/blob/master/vision/object_detection_segmentation/yolov4/dependencies/Conversion.ipynb
I ended up with a model with the following input and output layer dimensions
How can I determine the shape of the three output layers that have the unknown numbers?
I need them so I can use the model in ML.Net.

This is easy:
unk__2241 is batch size, so its unknown for now.
After CSPDarknet53, your output shape is (unk_2241,13,13,512) as reduce factor is 32. Then after SPP you have (unk_2241, 13, 13, 2048) with kernel size = [1,3,5,13].
You have 3 heads for detecting large, medium and small objects on image and 3 anchors per each of size of object. In this 3 heads yolo uses 3 feature maps which comes from modified PANet and this feature maps are (unk_2241,52,52,256), (unk_2241,26,26,512), (unk_2241,13,13,1024) as reduce factor is 8, 16, 32.
Then before each yolo layer, there is convolution for making final feature map and its shape is (unk_2241, 52, 52, 21), (unk_2241, 26, 26, 21) , (unk_2241, 13, 13, 21), and kernel shape is (256, (class number + coords of bbox + confidence)*anchor number for each size, 1, 1) ->(256, 21, 1, 1), (512, 21, 1, 1), (1024, 21, 1, 1).
And in yolo head you will have (unk_2241, 52, 52, 3, 7), (unk_2241, 26, 26, 3, 7), (unk_2241, 13, 13, 3, 7), where yolo head is dividing last axis of input by number of anchor, and number of class + coords of bbox + confidence.
As the result:
unk__2241 = unk__2242 = unk__2245 = unk__2248 -> They all batch sizes.
YOLO head output shapes: (unk_2242, 52, 52, 3, 7), (unk_2245, 26, 26, 3, 7), (unk_2248, 13, 13, 3, 7).
Batch size could be size of all dataset.

Related

Controlling Mutation in 39bit string as a candidate solution in genetic algorithm

I am working on an optimization problem. I have X number of ambulance locations, where X ranges from 1-39.
There are 43 numbers [Ambulance Locations] to choose from (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39) , we choose 3 of them since I have 3 ambulances.
I can only put my ambulance in three locations among 1-39 locations (Restriction). Assume that I want to put my Ambulance on the 5th, 19th, and 31 positions. -- Chromosome 1= [000010000000000000100000000000100000000]. In the above presentation, I am turning on 5-bit, 19-bit, and 31-bit.
Is it possible to flip a bit close to the original solution? For example, keeping 2 bits on in the original position and randomly changing the 3rd bit close to 2bits. It is important for me to keep 3bits on among 39bits. I want to make a control mutation with the aim to produce a small change.
My goal is to make small changes since each bit represents a location. The purpose of mutation is to make small changes and see evaluate results. Therefore, a code should do something like this. As for CS1: (111000000000000000000000000000000000000), I want something like (011010000000000000000000000000000000000), or (011001000000000000000000000000000000000), or (010110000000000000000000000000000000000) or (101010000000000000000000000000000000000), or (00101100000000000000000000000000000000), etc
To achieve mutation, what can be a good way to randomly change present positions to other positions keeping the range only between 1-39 locations (Restriction)?
you could use numpy and do something like
import numpy
s = "1110000000000000000000000000"
def mutate(s):
arr = numpy.array(list(s))
mask = arr == "1"
indices_of_ones = numpy.argwhere(mask).flatten()
pick_one_1_index = numpy.random.choice(indices_of_ones)
potential_swaps = numpy.argwhere(~mask).flatten()
distances = numpy.abs(pick_one_1_index - potential_swaps)
probabilities = (1/distances) # higher probabilities the less distance from its original position
# probabilities = (1/(distances*2)) # even higher probabilities the less distance from its original position
pick_one_0_index = numpy.random.choice(potential_swaps,p=probabilities/probabilities.sum())
arr[pick_one_1_index] = '0'
arr[pick_one_0_index] = '1'
return "".join(arr)
there is likely a more optimal solution
alternatively you can add a scalar or power to the distances to penalize more for distance...
if you wanted to test different multipliers or powers for the probabilities
you could use something like
def score_solution(s1,s2):
ix1 = set([i for i,v in enumerate(s1) if v == "1"])
ix2 = set([i for i,v in enumerate(s2) if v == "1"])
a,b = ix1 ^ ix2
return numpy.abs(a-b)
def get_solution_score_quantiles(sample_size=100,quantiles = [0.25,0.5,0.75]):
scores = []
for i in range(10):
s1 = mutate(s)
scores.append(score_solution(s,s1))
return numpy.quantile(scores,quantiles)
print(get_solution_score_quantiles(50))

Subtract two vectors of different size in C++

I have two vectors: one populated with a stride of 5, so it's size can be 5, 10, 15, 20, 25, 30 ... 5n.
And the other is populated with a stride of 6, so it's size is 6, 12, 18, 24, 30, 36 ... 6n
I'd like to subtract these two vectors as they were the same size. Since they both hold coordinates of a curve I thought I might subtract the middle two elements in the second vector so something like this:
// The numbers are indexes
(0, 1, 2, 3, 4, 5) =
(0, 1, 3 - 2, 4, 5)
The new size is 5. But it's not as easy on a general case when using a for loop to maintain and compare them both. The comparison should be something like this:
// The numbers are indexes
vector<int> v1 = (0, 1, 2, 3, 4, 5);
vector<int> v2 = (0, 1, 3 - 2, 4, 5);
vector<int> v3 = v1 - v2
Example:
// Actual numbers
vector<int> v1 = (110, 210, 310, 410, 510, 610, 710, 810, 910, 1010);
vector<int> v2 = (120, 220, 320, 420, 520, 620, 720, 820, 920, 1020, 1120, 1220);
vector<int> v3 = v1 - v2; // error - vectors different size
// so we try to fix it
v2 = (120, 220, (420 - 320), 520, 620, 720, 820, (920 - 1020), 1120, 1220);
v2 = (220, 100, 520, 620, 720, 820, 100, 1120, 1220); // resized vector in the desired fasion
v3 = v1 - v2; // still not ok - the vector is of the size 9.
Works just fine for the example of 1n but goes per shape when n > 1. How to do it, the same way, when the size of both vectors changes but they are always going to be populated the same number of times n? These vectors represent lines. I want to know the distances between each individual points in both vectors: so how far is the point v1[0] from the point v2[0] ect.

Halide: How to process image in (overlapping) blocks?

I'm discovering Halide and got some success with a pipeline doing various
transformations. Most of these are based on the examples within the sources (color-transformations, various filters, hist-eq).
My next step needs to process the image in blocks. In a more general form,
partially-overlapping blocks.
Examples
Input:
[ 1, 2, 3, 4, 5, 6, 7, 8,
9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29, 30, 31, 32]
Non-overlapping blocks:
Size: 2x4
[ 1, 2, 3, 4,
9, 10, 11, 12]
[ 5, 6, 7, 8,
13, 14, 15, 16]
[ 17, 18, 19, 20,
25, 26, 27, 28]
[ 21, 22, 23, 24,
29, 30, 31, 32]
Overlapping blocks:
Size: 2x4 with 50% overlap (both axes)
[ 1, 2, 3, 4,
9, 10, 11, 12]
[ 3, 4, 5, 6,
11, 12, 13, 14]
[ 5, 6, 7, 8,
13, 14, 15, 16]
-
[ 9, 10, 11, 12,
17, 18, 19, 20]
[11, 12, 13, 14,
19, 20, 21, 22]
...
I suspect there should be a nice way to express these, as those are also quite common
in many algorithms (e.g. macroblocks).
What i checked out
I tried to gather ideas from the tutorial and example apps and found the following,
which seem somewhat connected to what i want to implement:
Halide tutorial lesson 6: Realizing Funcs over arbitrary domains
// We start by creating an image that represents that rectangle
Image<int> shifted(5, 7); // In the constructor we tell it the size
shifted.set_min(100, 50); // Then we tell it the top-left corner
The problem i have: how to generalize this to multiple shifted domains without looping?
Halide tutorial lesson 9: Multi-pass Funcs, update definitions, and reductions
Here RDom is introduced which looks nice to create a block-view
Most examples using RDom seem to be sliding-window like approaches where there are no jumps
Target
So in general i'm asking how to implement a block-based view which can then be processed by
other steps.
It would be nice if the approach will be general enough to realize both, overlapping & no overlapping
Somehow generating the top-left indices first?
In my case, the image-dimension is known at compile-time which simplifies this
But i still would like some compact form which is nice to work with from Halide's perspective (no handcoded stuff like those examples with small filter-boxes)
The approach used might be depending on the output per block, which is a scalar in my case
Maybe someone can give me some ideas and/or some examples (which would be very helpful).
I'm sorry for not providing code, as i don't think i could produce anything helpful.
Edit: Solution
After dsharlet's answer and some tiny debugging/discussion here, the following very simplified self-containing code works (assuming an 1-channel 64x128 input like this one i created).
#include "Halide.h"
#include "Halide/tools/halide_image_io.h"
#include <iostream>
int main(int argc, char **argv) {
Halide::Buffer<uint8_t> input = Halide::Tools::load_image("TestImages/block_example.png");
// This is a simple example assuming an input of 64x128
std::cout << "dim 0: " << input.width() << std::endl;
std::cout << "dim 1: " << input.height() << std::endl;
// The "outer" (block) and "inner" (pixel) indices that describe a pixel in a tile.
Halide::Var xo, yo, xi, yi, x, y;
// The distance between the start of each tile in the input.
int tile_stride_x = 32;
int tile_stride_y = 64;
int tile_size_x = 32;
int tile_size_y = 64;
Halide::Func tiled_f;
tiled_f(xi, yi, xo, yo) = input(xo * tile_stride_x + xi, yo * tile_stride_y + yi);
Halide::RDom tile_dom(0, tile_size_x, 0, tile_size_y);
Halide::Func tile_means;
tile_means(xo, yo) = sum(Halide::cast<uint32_t>(tiled_f(tile_dom.x, tile_dom.y, xo, yo))) / (tile_size_x * tile_size_y);
Halide::Func output;
output(xo, yo) = Halide::cast<uint8_t>(tile_means(xo, yo));
Halide::Buffer<uint8_t> output_(2, 2);
output.realize(output_);
Halide::Tools::save_image(output_, "block_based_stuff.png");
}
Here's an example that breaks a Func into blocks of abitrary stride and size:
Func f = ... // The thing being blocked
// The "outer" (block) and "inner" (pixel) indices that describe a pixel in a tile.
Var xo, yo, xi, yi;
// The distance between the start of each tile in the input.
int tile_stride_x, tile_stride_y;
Func tiled_f;
tiled_f(xi, yi, xo, yo) = f(xo * tile_stride_x + xi, yo * tile_stride_y + yi);
Func tiled_output;
tiled_output(xi, yi, xo, yo) = ... // Your tiled processing here
To compute some reduction (like statistics) on each block, you can do the following:
RDom tile_dom(0, tile_size_x, 0, tile_size_y);
Func tile_means;
tile_means(xo, yo) = sum(tiled_output(tile_dom.x, tile_dom.y, xo, yo)) / (tile_size_x * tile_size_y);
To flatten the tiles back into a result is a bit tricky. It probably depends on your method of combining the results in overlapped areas. If you want to add up the overlapping tiles, the simplest way is probably to use an RDom:
RDom tiles_dom(
0, tile_size_x,
0, tile_size_y,
min_tile_xo, extent_tile_xo,
min_tile_yo, extent_tile_yo);
Func output;
Expr output_x = tiles_dom[2] * tile_stride_x + tiles_dom[0];
Expr output_y = tiles_dom[3] * tile_stride_y + tiles_dom[1];
output(x, y) = 0;
output(output_x, output_y) += tiled_output(tiles_dom[0], tiles_dom[1], tiles_dom[2], tiles_dom[3]);
Note that in the above two blocks of code, tile_stride_x and tile_size_x are independent parameters, allowing for any tile size and overlap.
In both of your examples, tile_size_x = 4, and tile_size_y = 2. To get non-overlapping tiles, set the tile strides equal to the tile size. To get 50% overlapping tiles, set tile_stride_x = 2, and tile_stride_y = 1.
A useful schedule for an algorithm like this is:
// Compute tiles as needed by the output.
tiled_output.compute_at(output, tile_dom[2]);
// or
tiled_output.compute_at(tile_means, xo);
There are other options, like using a pure func (no update/RDom) that uses the mod operator to figure out tile inner and outer indices. However, this approach can be difficult to schedule efficiently with overlapping tiles (depending on the processing you do at each tile). I use the RDom approach when this problem comes up.
Note that with the RDom approach, you have to supply the bounds of the tile indices you want computed (min_tile_xo, extent_tile_xo, ...), which can be tricky for overlapped tiles.

How to change matrix values to values from another matrix - Wolfram

I have just started my journey with Wolfram Mathematica and I want to implement a simple genetic algorithm. The construction of the data is given and I have to start with such rows/columns.
Here is what I have:
chromosome := RandomSample[CharacterRange["A", "G"], 7]
chromosomeList = Table[chromosome, 7] // MatrixForm
This gives me a matrix, where every row represents a chromosome:
yPos = Flatten[Position[chromosomeList, #], 1] & /# {"A", "B", "C",
"D", "E", "F", "G"};
yPos = yPos[[All, 3 ;; 21 ;; 3]] // Transpose
Now every column represents a letter (From A to G) and every row it's index in every chromosome:
Here is a given efficiency matrix, where very row represents different letter (From A to G) and every column gives the value that should be applied on the particular position:
efficiencyMatrix = {
{34, 31, 20, 27, 24, 24, 18},
{14, 14, 22, 34, 26, 19, 22},
{22, 16, 21, 27, 35, 25, 30},
{17, 21, 24, 16, 31, 22, 20},
{17, 29, 22, 31, 18, 19, 26},
{26, 29, 37, 34, 37, 20, 21},
{30, 28, 37, 28, 29, 23, 19}}
What I want to do is to create a matrix with values that correspond to the letter and it's position. I have done it like that:
values = Transpose[{ efficiencyMatrix[[1, yPos[[1]]]],
efficiencyMatrix[[2, yPos[[2]]]],
efficiencyMatrix[[3, yPos[[3]]]],
efficiencyMatrix[[4, yPos[[4]]]],
efficiencyMatrix[[5, yPos[[5]]]],
efficiencyMatrix[[6, yPos[[6]]]],
efficiencyMatrix[[7, yPos[[7]]]]}]
How can I write it in more elegant way?
You can apply a list of functions to some variable using the function Through, which is helpful when applying Position multiple times. Because Position[patt][expr] == Position[expr, patt], we can do
Through[ (Position /# CharacterRange["A","C"])[{"B", "C", "A"}] ]
to get {3, 1, 2}.
Position can also operate on lists, so we can simplify finding ypos by doing
Transpose#Map[Last, Through[(Position /# characters)[chromosomeList]], {2}]
where characters is the relevant output of CharacterRange.
We can also simplify dealing with ranges of integers by mapping over the Range function, so in total we end up with
characters = CharacterRange["A","G"]
efficiencies = ...
chromosomes = ...
ypos = Transpose#Map[Last, Through[(Position /# characters)[chromosomes]], {2}];
efficiencies[[#, ypos[[#]]]]& /# Range[Length[characters]] //Transpose ]

bitmap row size calculation

I found this source which works quite well, I just want to ask about this piece of code which I dont get:
//calculate total size of RGBQUAD scanlines (DWORD aligned)
bih.biSizeImage = (((bih.biWidth * 3) + 3) & 0xFFFC) * bih.biHeight ;
I get why there is "*3", but dont get the "+3" and the bitwise AND with FFFC hexa. Could someone explain me why he claculates size of the image this way?
Thanks
If you try that out for various values, you'll see it's actually forcing (width * 3) to round up to the smallest multiple of 4 that will contain it. He's probably doing this to enforce things to be 32-bit aligned.
Using python:
>>> f = lambda x: ((x * 3) + 3) & 0xFFFC
>>> [f(x) for x in range(1, 20)]
[4, 8, 12, 12, 16, 20, 24, 24, 28, 32, 36, 36, 40, 44, 48, 48, 52, 56, 60]
The following shows the difference between just doing the straight multiplication and rounding upwards towards a multiple of 4
>>> [(3*x, f(x)) for x in range(1, 8)]
[(3, 4), (6, 8), (9, 12), (12, 12), (15, 16), (18, 20), (21, 24)]
I'm surprised the code doesn't actually document this fact. Bit twiddling is a wonderful thing, but it can seem very arbitrary.