update naming so it matches RnExecutorchModule, added function to read image resource from base64, storage and external sources

Author: NorbertKlockiewicz

ios/RnExecutorch/StyleTransfer.mm

@@ -34,13 +34,7 @@ - (void)forward:(NSString *)input
         resolve:(RCTPromiseResolveBlock)resolve
          reject:(RCTPromiseRejectBlock)reject {
   @try {
-    NSURL *url = [NSURL URLWithString:input];
-    cv::Mat image = cv::imread([[url path] UTF8String], cv::IMREAD_COLOR);
-    if(image.empty()){
-      reject(@"img_loading_error", [NSString stringWithFormat:@"%ld", (long)InvalidArgument], nil);
-      return;
-    }
-    
+    cv::Mat image = [ImageProcessor readImage:input];
     cv::Mat resultImage = [model runModel:image];
 
     NSString* tempFilePath = [ImageProcessor saveToTempFile:resultImage];

ios/RnExecutorch/utils/ImageProcessor.h

@@ -6,5 +6,6 @@
 + (NSArray *)matToNSArray:(const cv::Mat &)mat;
 + (cv::Mat)arrayToMat:(NSArray *)array width:(int)width height:(int)height;
 + (NSString *)saveToTempFile:(const cv::Mat &)image;
++ (cv::Mat)readImage:(NSString *)source;
 
 @end

ios/RnExecutorch/utils/ImageProcessor.mm

@@ -55,4 +55,39 @@ + (NSString *)saveToTempFile:(const cv::Mat&)image {
   return outputPath;
 }
 
++ (cv::Mat)readImage:(NSString *)source {
+  NSURL *url = [NSURL URLWithString:source];
+  
+  cv::Mat inputImage;
+  NSLog(@"%@", url.scheme);
+  if([[url scheme] isEqualToString: @"data"]){
+    //base64
+    NSArray *parts = [source componentsSeparatedByString:@","];
+    if ([parts count] < 2) {
+        NSLog(@"Error: Data URI is not properly formatted");
+    }
+    NSString *encodedString = parts[1];
+    NSData *data = [[NSData alloc] initWithBase64EncodedString:encodedString options:NSDataBase64DecodingIgnoreUnknownCharacters];
+    cv::Mat encodedData(1, [data length], CV_8UC1, (void *)data.bytes);
+    inputImage = cv::imdecode(encodedData, cv::IMREAD_COLOR);
+  }
+  if([[url scheme] isEqualToString: @"file"]){
+    //local file
+    inputImage = cv::imread([[url path] UTF8String], cv::IMREAD_COLOR);
+  }
+  else {
+    //external file
+    NSData *data = [NSData dataWithContentsOfURL:url];
+    inputImage = cv::imdecode(cv::Mat(1, [data length], CV_8UC1, (void*)data.bytes), cv::IMREAD_COLOR);
+  }
+  
+  if(inputImage.empty()){
+    @throw [NSException exceptionWithName:@"readImage_error"
+                                   reason:[NSString stringWithFormat:@"%ld", (long)InvalidArgument]
+                                 userInfo:nil];
+  }
+  
+  return inputImage;
+}
+
 @end

src/StyleTransfer.ts

@@ -9,7 +9,7 @@ interface Props {
 
 interface StyleTransferModule {
   error: string | null;
-  isModelLoading: boolean;
+  isModelReady: boolean;
   isModelGenerating: boolean;
   forward: (input: string) => Promise<string>;
 }
@@ -18,7 +18,7 @@ export const useStyleTransfer = ({
   modulePath,
 }: Props): StyleTransferModule => {
   const [error, setError] = useState<null | string>(null);
-  const [isModelLoading, setIsModelLoading] = useState(true);
+  const [isModelReady, setIsModelReady] = useState(true);
   const [isModelGenerating, setIsModelGenerating] = useState(false);
 
   useEffect(() => {
@@ -30,23 +30,27 @@ export const useStyleTransfer = ({
       }
 
       try {
-        setIsModelLoading(true);
+        setIsModelReady(false);
         await StyleTransfer.loadModule(path);
       } catch (e) {
         setError(getError(e));
       } finally {
-        setIsModelLoading(false);
+        setIsModelReady(true);
       }
     };
 
     loadModel();
   }, [modulePath]);
 
   const forward = async (input: string) => {
-    if (isModelLoading) {
+    if (!isModelReady) {
       throw new Error(getError(ETError.ModuleNotLoaded));
     }
 
+    if (error) {
+      throw new Error(error);
+    }
+
     try {
       setIsModelGenerating(true);
       const output = await StyleTransfer.forward(input);
@@ -58,5 +62,5 @@ export const useStyleTransfer = ({
     }
   };
 
-  return { error, isModelLoading, isModelGenerating, forward };
+  return { error, isModelReady, isModelGenerating, forward };
 };