Error with "Extracting Colors from an Image"

[bnjmnsmith]

Hello Genius's!

I read some blog posts by various Alteryx and R artists on how to extract colors from an image. @BenMoss has an awesome one here that was extremely helpful, in fact I used his example more so than other ones. 

I'm having trouble with an error in the example Ben has on his blog. I've installed the png R package correctly (I believe), but I keep getting the error below. I've also attached the workbook I'm working in as well as the picture I wanted to use as an example (hidden in the .yxzp file). You'll need to change the filepath to make it work.

THANK YOU!!!

Error in seq.default(0,1, length.out = nrow(z))

This is the code I'm using:

## Open libraries required to complete analysis

library("png")
library("grid")
library("gridExtra")

## Read image into R. This will return a large array of elements
## which contains the RGB values (seperately) for each individual
## pixal within the image

image = readPNG("FILE PATH PLACEHOLDER")

## Convert the large array into a data frame containing 3 columns
## one for each of the three RGB values

df = data.frame(
	red = matrix(image(,,1), ncol=1),
	green = matrix(image(,,1), ncol=1),
	blue = matrix(image(,,1), ncol=1)
)

## Write our data frame for output

write.Alteryx(df, 1)

[BenMoss]

Hi @bnjmnsmith great to hear you are using the app.

Unfortunately i've not bumped into this error before; I can take a look at this potentially on Friday, but would you be able to share a sample image which is triggering this error.

Ben

[bnjmnsmith]

Here's what I'm looking at:

[BenMoss]

Sorry @bnjmnsmith I meant specifically the .png file that you are trying to load.

Ben

[BenMoss · Accepted solution]

I think you need to look at this part...

df = data.frame(
  red = matrix(image[,,1], ncol=1),
  green = matrix(image[,,1], ncol=1),
  blue = matrix(image[,,1], ncol=1)
)

It should look like this...

df = data.frame(
  red = matrix(image[,,1], ncol=1),
  green = matrix(image[,,2], ncol=1),
  blue = matrix(image[,,3], ncol=1)
)

[bnjmnsmith]

Hah! Oh, this thing. It's a simple picture I created to practice on.

[bnjmnsmith]

You are absolutely right about the code. I corrected it as you said. Unfortunately the error is still popping up.

Thank you for your help!!!

[bnjmnsmith]

Wait!!! I should have looked at this better...I was using parenthesis ( ) instead of brackets [ ]. It works like a charm now!

Thank you for helping me @BenMoss!