phototext.R

library(shiny)
library(magick)

ui <- fluidPage(
  titlePanel("Image Upload and Text Overlay"),
  sidebarLayout(
    sidebarPanel(
      fileInput("file1", "Choose an Image File",
                accept = c('image/png', 'image/jpeg')),
      textInput("text_topleft", "Text for Top Left", ""),
      selectInput("fontsize", "Font Size (pixels)",
                  choices = c(64, 128, 256, 384, 512),
                  selected = 128),
      selectInput("color", "Text Color",
                  choices = c("white", "black", "yellow"),
                  selected = "white"),
      downloadButton("downloadImage", "Download Image")
    ),
    mainPanel(
      tags$style(type="text/css", "#image img {max-width: 100%; height: auto;}"),
      imageOutput("image")
    )
  )
)

server <- function(input, output) {
  output$image <- renderImage({
    req(input$file1)
    img <- image_read(input$file1$datapath)
    
    positions <- list(
      topleft = "+20+20")
    
    texts <- list(
      input$text_topleft
    )
    
    for (i in seq_along(texts)) {
      if (texts[[i]] != "") {
        img <- image_annotate(img, texts[[i]], size = as.numeric(input$fontsize), location = positions[[i]], color = input$color)
      }
    }
    
    tmpfile <- tempfile(fileext = 'jpg')
    image_write(img, tmpfile)
    
    list(src = tmpfile, contentType = 'image/png', alt = "Uploaded Image")
  }, deleteFile = TRUE)
  
  output$downloadImage <- downloadHandler(
    filename = function() {
      paste("modified_image", Sys.Date(), ".jpg", sep = "")
    },
    content = function(file) {
      req(input$file1)
      img <- image_read(input$file1$datapath)
      
      positions <- list(
        topleft = "+20+20")
      
      texts <- list(
        input$text_topleft)
      
      for (i in seq_along(texts)) {
        if (texts[[i]] != "") {
          img <- image_annotate(img, texts[[i]], size = as.numeric(input$fontsize), location = positions[[i]], color = input$color)
        }
      }
      
      image_write(img, file)
    }
  )
}

shinyApp(ui, server)