How to open an image? - r

Question

enter image description here
I use 'openImage' package to import multiple images,
#this sets the directory
list\<- list.files("C://Users//Bilal//Desktop//test//bb", all.files
= FALSE,full.names = TRUE)
#this loop to import the images
df<-data.frame()
#df <-list()
for (i in seq_along(lista)) {
pic<-readImage(lista[i])
pic<-rgb_2gray(pic)
pic<-resizeImage(pic, width = 48, height = 64)
pic<-as.vector(pic)
pre_pic<-t(pic)
df<-rbind(df,pre_pic)}
#this code is used to open the image but the second line does not work
#Error in image.default(df, xaxt = "n", yaxt = "n", col = grayscale) :
#'z' must be a matrix
grayscale <- gray(seq(0, 1, length = 100))
image(df[,,1], xaxt='n', yaxt='n', col=grayscale)
This is what I expect to see

Answer 1

I understand now what's happening; thanks for sharing the image. First- you were/are using grDevices::image() <- the base R function.
The error tells you that R can't determine how you shaped your data. When you flattened the matrix into a vector, you knew it was 48 x 64, but that information wasn't there when you sent it to image.
You could do either one of the following:
# before making it a vector
image(t(p3), col = grayscale, yaxt = 'n', xaxt = 'n')
# after making it a row in a data frame
image(t(matrix(unlist(df[1,]), ncol = 64, nrow = 48)),
col = grayscale, yaxt = 'n', xaxt = 'n')