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
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
#include <opencv2/core.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/imgcodecs.hpp>
#include <iostream>
#include <vector>
using namespace std;
using namespace cv;
int main(int /*argc*/, const char** /* argv */ )
{
Mat framebuffer( 160 * 2, 160 * 5, CV_8UC3, cv::Scalar::all(255) );
Mat img( 160, 160, CV_8UC3, cv::Scalar::all(255) );
// Create test image.
{
const Point center( img.rows / 2 , img.cols /2 );
for( int radius = 5; radius < img.rows ; radius += 3 )
{
cv::circle( img, center, radius, Scalar(255,0,255) );
}
cv::rectangle( img, Point(0,0), Point(img.rows-1, img.cols-1), Scalar::all(0), 2 );
}
// Draw original image(s).
int top = 0; // Upper images
{
for( int left = 0 ; left < img.rows * 5 ; left += img.rows ){
Mat roi = framebuffer( Rect( left, top, img.rows, img.cols ) );
img.copyTo(roi);
cv::putText( roi, "original", Point(5,15), FONT_HERSHEY_SIMPLEX, 0.5, Scalar::all(0), 2, 4, false );
}
}
// Draw lossy images
top += img.cols; // Lower images
{
struct test_config{
string comment;
uint32_t sampling_factor;
} config [] = {
{ "411", IMWRITE_JPEG_SAMPLING_FACTOR_411 },
{ "420", IMWRITE_JPEG_SAMPLING_FACTOR_420 },
{ "422", IMWRITE_JPEG_SAMPLING_FACTOR_422 },
{ "440", IMWRITE_JPEG_SAMPLING_FACTOR_440 },
{ "444", IMWRITE_JPEG_SAMPLING_FACTOR_444 },
};
const int config_num = 5;
int left = 0;
for ( int i = 0 ; i < config_num; i++ )
{
// Compress images with sampling factor parameter.
vector<int> param;
param.push_back( IMWRITE_JPEG_SAMPLING_FACTOR );
param.push_back( config[i].sampling_factor );
vector<uint8_t> jpeg;
(void) imencode(".jpg", img, jpeg, param );
// Decompress it.
Mat jpegMat(jpeg);
Mat lossy_img = imdecode(jpegMat, -1);
// Copy into framebuffer and comment
Mat roi = framebuffer( Rect( left, top, lossy_img.rows, lossy_img.cols ) );
lossy_img.copyTo(roi);
cv::putText( roi, config[i].comment, Point(5,155), FONT_HERSHEY_SIMPLEX, 0.5, Scalar::all(0), 2, 4, false );
left += lossy_img.rows;
}
}
// Output framebuffer(as lossless).
imwrite( "imgcodecs_jpeg_samplingfactor_result.png", framebuffer );
return 0;
}
|
