Support for batches and no downloads

R/googleVision-LIB.R

@@ -16,11 +16,16 @@
 #' @param imagePath provide path/url to image
 #' @return get the image back as encoded file
 #'
-imageToText <- function(imagePath) {
+imageToText <- function(imagePath, download) {
 
   if (stringr::str_count(imagePath, "http")>0) {### its a url!
-    content <- RCurl::getBinaryURL(imagePath)
-    txt <- RCurl::base64Encode(content, "txt")
+    if (identical(download, FALSE)) {
+      txt <- imagePath
+    }
+    else {
+      content <- RCurl::getBinaryURL(imagePath)
+      txt <- RCurl::base64Encode(content, "txt")
+    }
   } else {
     txt <- RCurl::base64Encode(readBin(imagePath, "raw", file.info(imagePath)[1, "size"]), "txt")
   }
@@ -32,25 +37,20 @@ imageToText <- function(imagePath) {
 #' @description a utility to extract features from the API response
 #'
 #' @param pp an API response object
-#' @param feature the name of the feature to return 
+#' @param feature the name of the feature to return
 #' @return a data frame
 #'
 extractResponse <- function(pp, feature){
-  if (feature == "LABEL_DETECTION") {
-    return(pp$content$responses$labelAnnotations[[1]])
-  }
-  if (feature == "FACE_DETECTION") {
-    return(pp$content$responses$faceAnnotations[[1]])
-  }
-  if (feature == "LOGO_DETECTION") {
-    return(pp$content$responses$logoAnnotations[[1]])
-  }
-  if (feature == "TEXT_DETECTION") {
-    return(pp$content$responses$textAnnotations[[1]])
-  }
-  if (feature == "LANDMARK_DETECTION") {
-    return(pp$content$responses$landmarkAnnotations[[1]])
-  }
+  feature_map <- list(
+    LABEL_DETECTION    = "labelAnnotations",
+    FACE_DETECTION     = "faceAnnotations",
+    LOGO_DETECTION     = "logoAnnotations",
+    TEXT_DETECTION     = "textAnnotations",
+    LANDMARK_DETECTION = "landmarkAnnotations"
+  )
+
+  feature_name <- feature_map[[feature]]
+  do.call("rbind", pp$content$responses[[feature_name]])
 }
 
 
@@ -61,24 +61,44 @@ extractResponse <- function(pp, feature){
 #' @param imagePath path or url to the image
 #' @param feature one out of: FACE_DETECTION, LANDMARK_DETECTION, LOGO_DETECTION, LABEL_DETECTION, TEXT_DETECTION
 #' @param numResults the number of results to return.
+#' @param download should image urls be downloaded and sent as data to the API?
 #' @export
 #' @return a data frame with results
-#' @examples 
+#' @examples
 #' f <- system.file("exampleImages", "brandlogos.png", package = "RoogleVision")
 #' getGoogleVisionResponse(imagePath = f, feature = "LOGO_DETECTION")
 #' @import googleAuthR
 #'
-getGoogleVisionResponse <- function(imagePath, feature = "LABEL_DETECTION", numResults = 5){
+getGoogleVisionResponse <- function(imagePath,
+                                    feature = "LABEL_DETECTION",
+                                    numResults = 5,
+                                    download = TRUE){
 
   #################################
-  txt <- imageToText(imagePath)
-  ### create Request, following the API Docs.
-  if (is.numeric(numResults)) { 
-    body <- paste0('{  "requests": [    {   "image": { "content": "',txt,'" }, "features": [  { "type": "',feature,'", "maxResults": ',numResults,'} ],  }    ],}')
-  } else {
-    body <- paste0('{  "requests": [    {   "image": { "content": "',txt,'" }, "features": [  { "type": "',feature,'" } ],  }    ],}')
+  requests <- c()
+
+  for (singlePath in imagePath) {
+    txt <- imageToText(singlePath, download = download)
+
+    if (identical(download, FALSE)) {
+      imageContent <- paste0('"image": { "source": { "imageUri": "',txt,'" } }')
+    }
+    else {
+      imageContent <- paste0('"image": { "content": "',txt,'" }')
+    }
+
+    ### create Request, following the API Docs.
+    if (is.numeric(numResults)) {
+      request <- paste0('{   ', imageContent, ', "features": [  { "type": "',feature,'", "maxResults": ',numResults,'} ],  }')
+    } else {
+      request <- paste0('{   ', imageContent, ', "features": [  { "type": "',feature,'" } ],  }')
+    }
+
+    requests <- c(requests, request)
   }
 
+  body <- paste0('{  "requests": [    ', paste0(requests, collapse = ", ") , '    ],}')
+
   simpleCall <- gar_api_generator(baseURI = "https://vision.googleapis.com/v1/images:annotate", http_header = "POST")
   ## set the request!
   pp <- simpleCall(the_body = body)