Task
Our task is to find the center of the head in each image.
To achieve the goal, we need to do the following:
- upload images with
DataBlock - add red points to the images
Upload an example:
library(fastai)
library(magrittr)
path = 'biwi_head_pose'
fname = '09/frame_00667_rgb.jpg'
img = Image_create(paste(path,fname,sep = '/'))
img %>% show() %>% plot()
cal = readr::read_lines(paste(path,'01/rgb.cal',sep = '/'), n_max = 3) %>% trimws() %>%
strsplit('\\s') %>% do.call(rbind,.) %>% apply(.,2,as.numeric)
To add the points, we need to write simple functions:
img2txt_name <- function(f) {
paste(
substr(f, 1, nchar(f)-7), 'pose.txt',
sep = ''
)
}
convert_biwi <- function(coords) {
c1 = coords[1] * cal[1,][1]/coords[3] + cal[1,][3]
c2 = coords[2] * cal[2,][2]/coords[3] + cal[2,][3]
return(tensor(c1,c2))
}
get_ctr <- function(f) {
# trick to make dataloaders work
f = as.character(f)
ctr = readr::read_lines(img2txt_name(f), skip = 4, n_max = 1) %>% trimws() %>%
strsplit('\\s') %>% unlist() %>% as.numeric()
convert_biwi(ctr)
}
get_ip <- function(img, pts) {
TensorPoint_create(pts, img_size = img$size)
}ctr = readr::read_lines(img2txt_name(paste(path,fname,sep = '/')),
skip = 4, n_max = 1) %>% trimws() %>%
strsplit('\\s') %>% unlist() %>% as.numeric()Now, it is easier to add red points:
ctr = get_ctr(paste(path,fname,sep = '/'))
ax = img %>% show(figsize = c(6, 6))
img %>% get_ip(ctr) %>% show(ctx = ax) %>% plot()
