Custom background colour

android/src/main/java/com/backgroundremover/BackgroundRemoverModule.kt

@@ -31,7 +31,7 @@ class BackgroundRemoverModule internal constructor(context: ReactApplicationCont
   }
 
   @ReactMethod
-  override fun removeBackground(imageURI: String, promise: Promise) {
+  override fun removeBackground(imageURI: String, redValue: Int, greenValue: Int, blueValue: Int, promise: Promise) {
     val segmenter = this.segmenter ?: createSegmenter()
     val image = getImageBitmap(imageURI)
 
@@ -45,14 +45,19 @@ class BackgroundRemoverModule internal constructor(context: ReactApplicationCont
 
       for (y in 0 until result.height) {
         for (x in 0 until result.width) {
-          val alpha = maskBuffer.getFloat().pow(4)
-          mask.setPixel(x, y, Color.argb((alpha * 255).toInt(), 0, 0, 0))
+          val alpha = maskBuffer.getFloat()
+          if (alpha < 0.5f) {
+            image.setPixel(x, y, Color.rgb(redValue, greenValue, blueValue))
+          }
+          else {
+            mask.setPixel(x, y, Color.argb((alpha * 255).toInt(), 255, 255, 255))
+          }
         }
       }
 
       val paint = Paint(Paint.ANTI_ALIAS_FLAG)
       paint.setXfermode(PorterDuffXfermode(PorterDuff.Mode.DST_IN))
-      val canvas = Canvas(image)
+      val canvas = Canvas()
       canvas.drawBitmap(mask, 0f, 0f, paint)
 
       val fileName = URI(imageURI).path.split("/").last()

android/src/oldarch/BackgroundRemoverSpec.kt

@@ -7,5 +7,5 @@ import com.facebook.react.bridge.Promise
 abstract class BackgroundRemoverSpec internal constructor(context: ReactApplicationContext) :
   ReactContextBaseJavaModule(context) {
 
-  abstract fun removeBackground(imageURI: String, promise: Promise)
+  abstract fun removeBackground(imageURI: String, redValue: Int, greenValue: Int, blueValue: Int, promise: Promise)
 }

ios/ReactNativeBackgroundRemover.mm

@@ -1,5 +1,5 @@
 #import "ReactNativeBackgroundRemover.h"
-#import "ReactNativeBackgroundRemover-Swift.h"
+#import "ReactNativeBackgroundRemover/ReactNativeBackgroundRemover-Swift.h"
 
 @implementation BackgroundRemover {
   BackgroundRemoverSwift *backgroundRemover;
@@ -18,10 +18,18 @@ - (id)init {
 }
 
 RCT_EXPORT_METHOD(removeBackground:(NSString *)imageURI
-                 resolve:(RCTPromiseResolveBlock)resolve
+                  redValue:(NSInteger)redValue
+                  greenValue:(NSInteger)greenValue
+                  blueValue:(NSInteger)blueValue
+                  resolve:(RCTPromiseResolveBlock)resolve
                   reject:(RCTPromiseRejectBlock)reject)
 {
-    [backgroundRemover removeBackground:imageURI resolve:resolve reject:reject];
+    [backgroundRemover removeBackground:imageURI
+                               redValue:redValue
+                             greenValue:greenValue
+                              blueValue:blueValue
+                                resolve:resolve
+                                 reject:reject];
 }
 
 // Don't compile this code when we build for the old architecture.

ios/ReactNativeBackgroundRemover.swift

@@ -4,7 +4,7 @@ import CoreImage
 public class BackgroundRemoverSwift: NSObject {
 
     @objc
-    public func removeBackground(_ imageURI: String, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock)->Void {
+    public func removeBackground(_ imageURI: String, redValue: Int, greenValue: Int, blueValue: Int, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock)->Void {
         #if targetEnvironment(simulator)
         reject("BackgroundRemover", "SimulatorError", NSError(domain: "BackgroundRemover", code: 2))
             return
@@ -31,11 +31,18 @@ public class BackgroundRemoverSwift: NSObject {
                     let scaleY = originalImage.extent.height / maskImage.extent.height
                     maskImage = maskImage.transformed(by: .init(scaleX: scaleX, y: scaleY))
 
-                    let maskedImage = originalImage.applyingFilter("CIBlendWithMask", parameters: [kCIInputMaskImageKey: maskImage])
+                    // Create a solid color background image
+                    let backgroundColor = CIColor(red: CGFloat(redValue) / 255.0, green: CGFloat(greenValue) / 255.0, blue: CGFloat(blueValue) / 255.0)
+                    let backgroundImage = CIImage(color: backgroundColor).cropped(to: originalImage.extent)
+
+                    let maskedImage = originalImage.applyingFilter("CIBlendWithMask", parameters: [kCIInputImageKey: originalImage,kCIInputMaskImageKey: maskImage])
+
+                    // Combine the masked image with the background
+                    let finalImage = maskedImage.composited(over: backgroundImage)
 
                     // Save the masked image to a temporary file
                     let tempURL = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(url.lastPathComponent)
-                    let uiImage = UIImage(ciImage: maskedImage)
+                    let uiImage = UIImage(ciImage: finalImage)
                     if let data = uiImage.pngData() {
                         try data.write(to: tempURL)
                         resolve(tempURL.absoluteString)

src/NativeBackgroundRemover.ts

@@ -1,8 +1,9 @@
 import type { TurboModule } from 'react-native';
 import { TurboModuleRegistry } from 'react-native';
+import { Int32 } from 'react-native/Libraries/Types/CodegenTypes';
 
 export interface Spec extends TurboModule {
-  removeBackground(imageURI: string): Promise<string>;
+  removeBackground(imageURI: string, redValue: Int32, greenValue: Int32, blueValue: Int32): Promise<string>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>('BackgroundRemover');

src/index.tsx

@@ -1,4 +1,5 @@
 import { NativeModules, Platform } from 'react-native';
+import { Int32 } from 'react-native/Libraries/Types/CodegenTypes';
 
 const LINKING_ERROR =
   `The package 'react-native-background-remover' doesn't seem to be linked. Make sure: \n\n` +
@@ -32,9 +33,9 @@ const BackgroundRemover = BackgroundRemoverModule
  * @throws Error if the iOS device is not at least on iOS 15.0.
  * @throws Error if the image could not be processed for an unknown reason.
  */
-export async function removeBackground(imageURI: string): Promise<string> {
+export async function removeBackground(imageURI: string, redValue: Int32, greenValue: Int32, blueValue: Int32): Promise<string> {
   try {
-    const result: string = await BackgroundRemover.removeBackground(imageURI);
+    const result: string = await BackgroundRemover.removeBackground(imageURI, redValue, greenValue, blueValue);
     return result;
   } catch (error) {
     if (error instanceof Error && error.message === 'SimulatorError') {