STM32光流

Kevincoooool · 发表于 2018-2-7 14:42:19

之前一直是用的PIXFLOW和匿名的光流所以一直想自己做一个理解一下其中的过程
匿名的只是为了赚钱所以不开源只有看pixflow的源码了
其中截取了一部分复制到了自己的工程里

///////////////////////////////////////////////////////
//函数功能：检测某点是否是特征点
///////////////////////////////////////////////////////
static inline uint32_t compute_diff(uint8_t *image, uint16_t offX, uint16_t offY, uint16_t row_size)
{
uint16_t off = (offY + 2) * row_size + (offX + 2); // we calc only the 4x4 pattern
uint32_t acc;
//4*4像素向下求差，再累加
acc = __USAD8 (*((uint32_t*) &image[off + 0 + 0 * row_size]), *((uint32_t*) &image[off + 0 + 1 * row_size]));
acc = __USADA8(*((uint32_t*) &image[off + 0 + 1 * row_size]), *((uint32_t*) &image[off + 0 + 2 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image[off + 0 + 2 * row_size]), *((uint32_t*) &image[off + 0 + 3 * row_size]), acc);
//4*4像素向右求差，再累加
uint32_t col1 = (image[off + 0 + 0 * row_size] << 24) | image[off + 0 + 1 * row_size] << 16 | image[off + 0 + 2 * row_size] << 8 | image[off + 0 + 3 * row_size];
uint32_t col2 = (image[off + 1 + 0 * row_size] << 24) | image[off + 1 + 1 * row_size] << 16 | image[off + 1 + 2 * row_size] << 8 | image[off + 1 + 3 * row_size];
uint32_t col3 = (image[off + 2 + 0 * row_size] << 24) | image[off + 2 + 1 * row_size] << 16 | image[off + 2 + 2 * row_size] << 8 | image[off + 2 + 3 * row_size];
uint32_t col4 = (image[off + 3 + 0 * row_size] << 24) | image[off + 3 + 1 * row_size] << 16 | image[off + 3 + 2 * row_size] << 8 | image[off + 3 + 3 * row_size];
//全部累加
acc = __USADA8(col1, col2, acc);
acc = __USADA8(col2, col3, acc);
acc = __USADA8(col3, col4, acc);
return acc;
}

[color=rgb(51, 102, 153) !important]复制代码

///////////////////////////////////////////////////////
//函数功能：比较两副8X8像素图片的相似度
///////////////////////////////////////////////////////
static inline uint32_t compute_sad_8x8(uint8_t *image1, uint8_t *image2, uint16_t off1X, uint16_t off1Y, uint16_t off2X, uint16_t off2Y, uint16_t row_size)
{
uint16_t off1 = off1Y * row_size + off1X; // image1
uint16_t off2 = off2Y * row_size + off2X; // image2
//两副8*8像素对应相减，再累加
uint32_t acc;
//第一行相减，再累加
acc = __USAD8 (*((uint32_t*) &image1[off1 + 0 + 0 * row_size]), *((uint32_t*) &image2[off2 + 0 + 0 * row_size]));
acc = __USADA8(*((uint32_t*) &image1[off1 + 4 + 0 * row_size]), *((uint32_t*) &image2[off2 + 4 + 0 * row_size]), acc);
//第二行相减，再累加，依次类推
acc = __USADA8(*((uint32_t*) &image1[off1 + 0 + 1 * row_size]), *((uint32_t*) &image2[off2 + 0 + 1 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 4 + 1 * row_size]), *((uint32_t*) &image2[off2 + 4 + 1 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 0 + 2 * row_size]), *((uint32_t*) &image2[off2 + 0 + 2 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 4 + 2 * row_size]), *((uint32_t*) &image2[off2 + 4 + 2 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 0 + 3 * row_size]), *((uint32_t*) &image2[off2 + 0 + 3 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 4 + 3 * row_size]), *((uint32_t*) &image2[off2 + 4 + 3 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 0 + 4 * row_size]), *((uint32_t*) &image2[off2 + 0 + 4 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 4 + 4 * row_size]), *((uint32_t*) &image2[off2 + 4 + 4 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 0 + 5 * row_size]), *((uint32_t*) &image2[off2 + 0 + 5 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 4 + 5 * row_size]), *((uint32_t*) &image2[off2 + 4 + 5 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 0 + 6 * row_size]), *((uint32_t*) &image2[off2 + 0 + 6 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 4 + 6 * row_size]), *((uint32_t*) &image2[off2 + 4 + 6 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 0 + 7 * row_size]), *((uint32_t*) &image2[off2 + 0 + 7 * row_size]), acc);
acc = __USADA8(*((uint32_t*) &image1[off1 + 4 + 7 * row_size]), *((uint32_t*) &image2[off2 + 4 + 7 * row_size]), acc);
return acc;
}

[color=rgb(51, 102, 153) !important]复制代码

然后每隔4个像素来找特征点

//上下左右循环移动4个像素对比图片相似度
for(int8_t yy=winmin; yy<=winmax; yy++)
{
for(int8_t xx=winmin; xx<=winmax; xx++)
{
//计算匹配度
temp_match = compute_sad_8x8(image_new, image_old, x, y, x + xx, y + yy, wid);
//寻找最小值，越小越相似
if (temp_match < match_min)
{
sumx = xx;
sumy = yy;
match_min = temp_match;
}
}
}

[color=rgb(51, 102, 153) !important]复制代码

最后实际的效果还不错就是激光模块给手焊坏了

Kevincoooool · 发表于 2018-2-21 17:33:28

哇没人

civic7366 · 发表于 2018-2-23 17:30:58

我前陣子也看完PX4FLOW代碼....你說效果不錯是如何驗證的?

Kevincoooool · 发表于 2018-2-23 19:36:43

civic7366 发表于 2018-2-23 17:30
我前陣子也看完PX4FLOW代碼....你說效果不錯是如何驗證的?

安装在了小四轴上定点的效果不错的而且光流的波形和匿名光流的波形对比了差不多的

炫色康康 · 发表于 2018-2-24 08:52:50

也在看飞控，还得多学习

Kevincoooool · 发表于 2018-2-24 16:30:44

炫色康康发表于 2018-2-24 08:52
也在看飞控，还得多学习

可以

civic7366 · 发表于 2018-2-26 11:33:00

樓主~~~~請問你用的影像感測器是哪一款?

Kevincoooool · 发表于 2018-2-26 12:34:46

civic7366 发表于 2018-2-26 11:33
樓主~~~~請問你用的影像感測器是哪一款?

OV7740 你的PIXflow有MDK的代码？

civic7366 · 发表于 2018-2-26 15:03:32

有..在掏寶買的但是透過JTAG燒寫之後PX4FLOW就掛了
仿真看它PC指針會跑到很奇怪的地方嘗試刪掉一些可能跑飛的函數
發現連for迴圈都能跑飛...每次跑飛得地方都可以不一樣
不知到啥問題...無解...

civic7366 · 发表于 2018-2-26 15:20:23

我原本想說自己修復它(自己從頭外設初始化), 結果用了原子的工程模板燒下去把它燒壞了...
應該是PX4FLOW外部晶振不是8M的, 好像是12M還是16M...
套用原本的PLL倍頻係數下去的sysclk直接把F407玩壞了...
其實我不會寫UVC...搞到最後看不到影像也是問題
更不想去看那個mavlink協議...

我有把程式碼移植到PC 隨便拿一個PCAM裝置實驗過效果了
感覺誤差還是挺大...用2把直尺固定住板子照牆壁作平移測試

01shuif2aw · 发表于 2019-1-18 11:22:31

学习学习，谢谢楼主

octssss · 发表于 2021-10-14 15:56:24

没事也想自己做一个玩，但是遇到点摄像头格式转换的问题，能请教一下，摄像头什么格式输出吗

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STM32光流

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