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Showing posts with label color. Show all posts
Showing posts with label color. Show all posts

Sunday, February 11, 2024

Taylor Swift and Data Analysis

Taylor Swift and Data Analysis. by Jerry Tuttle

Who will be the most talked-about celebrity before, during, and after the Super Bowl?

She is an accomplished performer. songwriter, businesswoman, and philanthropist. I think she is very pretty. And those lips!

So what can a data analyst add to everything that has been said about her?

I was curious whether R could identify her lipstick color. I should preface this by saying I have some degree of color-challengedness, although I am not colorblind. I am also aware that you can Google something like "what lipstick shade does taylor swift use" and you will get many replies. But I am more interested in an answer like E41D4F. I do wonder if I could visit a cosmetics store and say, "I'd like to buy a lipstick for my wife. Do you have anything in E41D4F ?"

There are sites that take an image, allow you to hover over a particular point, and the site will attempt to identify the computer color. Here is one: RedKetchup But I want a more R-related approach. A note on computers and colors: A computer represents an image in units called pixels. Each pixel contains a combination of base sixteen numbers for red, green and blue. A base 16 number ranges from 0 through F. Each of red, green and blue is a two-digit base 16 number, so a full number is a six-digit base 16 number. There are 16^ 6 = 16,777,216 possible colors. E41D4F is one of those 16.8 million colors.

There are R packages that will take an image and identify the most frequent colors. I tried this with the image above, and I got unhelpful colors. This is because the image contains the background, her hair, her clothing, and lots of other things unrelated to her lips. If you think about it, the lips are really a small portion of a face anyway. So I need to narrow down the image to her lips.

I plotted the image on a rectangular grid, using the number of columns of the image file as the xlimit width, and the number of rows as the ylimit height. Then by trial and error I manually found the coordinates of a rectangle for the lips. The magick library allows you to crop an image, using this crop format:

<width>x<height>{+-}<xoffset>{+-}<yoffset> The y offset is from the top, not the bottom. The cropped image can be printed.

The package colouR will then identify the most frequent colors. I found it necessary to save the cropped image to my computer and then read it back in because colouR would not accept it otherwise. The getTopCol command will extract the top colors by frequency. I assume it is counting frequency of hex color codes among the pixel elements. Here is a histogram of the result:

Really? I'm disappointed. Although I am color-challenged, this can't be right.

I have tried this with other photos of Taylor. I do get that she wears more than one lipstick color. I have also learned that with 16.8 million colors, perhaps the color is not identical on the entire lip - maybe some of you lipstick aficionados have always known this. All of these attempts have been somewhat unsatisfactory. There are too many colors on the graph that seem absolutely wrong, and no one color seems to really capture her shade, at least as I perceive it. Any suggestions from the R community?

No matter who you root for in the Super Bowl - go Taylor.

Here is my R code:

library(png)
library(ggplot2)
library(grid)
library(colouR)
library(magick)

xpos <- c(0,0,0)
ypos <- c(0,0,0)
df <- data.frame(xpos = xpos, ypos = ypos)

# downloaded from
# https://img.etimg.com/thumb/msid-100921419,width-300,height-225,imgsize-50890,resizemode-75/taylor-swift-mitchell-taebel-from-indiana-arrested-for-stalking-threatening-singer.jpg

img <- "C:/Users/Jerry/Desktop/R_files/taylor/taylor_swift.png"
img <- readPNG(img, native=TRUE)
height <- nrow(img) # 457
width <- ncol(img) # 584
img <- rasterGrob (img, interpolate = TRUE)

# print onto grid
ggplot(data = df,
aes(xpos, ypos)) +
xlim(0, width) + ylim(0, height) +
geom_blank() +
annotation_custom(img, xmin=0, xmax=width, ymin=0, ymax=height)

#############################################
# choose dimensions of subset rectangle

width <- 105
height <- 47
x1 <- 215 # from left
y1 <- 300 # from top

library(magick)
# must read in as magick object
img <- image_read('C:/Users/Jerry/Desktop/R_files/taylor/taylor_swift.png')
# print(img)

# crop format: x{+-}{+-}
cropped_img <- image_crop(img, "105x47+215+300")
print(cropped_img) # lips only
image_write(cropped_img, path = "C:/Users/Jerry/Desktop/R_files/taylor/lips1.png", format = "png")

##############################################

# extract top colors of lips image

top10 <- colouR::getTopCol(path = "C:/Users/Jerry/Desktop/R_files/taylor/lips1.png",
n = 10, avgCols = FALSE, exclude = FALSE)
top10

# plot
ggplot(top10, aes(x = hex, y = freq, , fill = hex)) +
geom_bar(stat = 'identity') +
labs(title="Top 10 colors by frequency") +
xlab("HEX colour code") + ylab("Frequency") +
theme(
legend.position="NULL",
plot.title = element_text(size=15, face="bold"),
axis.title = element_text(size=15, face="bold"),
axis.text.x = element_text(angle = 45, hjust = 1, size=12, face="bold"))

# End
##################################################################################

Thursday, February 7, 2013

The color-challenged math student



If you are part of the 92% majority (that was not supposed to be a political comment), then you can see a number inside that circle.  But I can't.  The common description for my condition is being colorblind, although I prefer the more politically correct "color-challenged".  I am not truly colorblind.  I see some colors, just not as many as you see, and I get especially confused between red and green, shades of red and green, and colors containing either red or green (for example blue versus purple).

I will stop my car for the top (or left) traffic light, but I don't really think it is red. I would wear a red tie with a green-striped shirt if no one stops me, so I try not to own shirts with green.  Or to wear ties.  I'm never quite sure if the meat is cooked enough. You won't see me choosing colors of house paint or women's makeup shades, and I won't be disabling colored wires for the police bomb squad.  So generally I have learned to live with this minor inconvenience, and the accompanying jokes, which has not impeded my career choice.

But the world of math is not as black and white as it used to be.  A textbook author would never graph two curves in the same color.  But if y = .5ex  is in red and y = x2 is in green, I am going to be confused as to which curve is greater in 1 < x < 3.  I also get confused by multi-color pie charts where some of those colors start to blend together.  And if you really want to lose me, just show me one of those colored maps with ten or so different colors representing ten different levels of the amount of rainfall.

So if you are a teacher with control over such things, please be aware that some small percent of your students could be color-challenged and they may not even know it.  The best thing you can do is provide labels in addition to different colors.  Another possibility is to provide different kinds of patterns (see Excel's FORMAT, FILL, PATTERN STYLES).  Lastly, choose among colors we are more likely to recognize, and especially avoid red AND green together.

Have you had any difficulties in math with a color-challenged math student?