fix ios CPU preprocess test=develop (#1972)

* fix ios CPU preprocess test=develop

* fix style test=develop

.pre-commit-config.yaml

@@ -36,7 +36,7 @@ repos:
         entry: bash ./tools/codestyle/cpplint_pre_commit.hook
         language: system
         files: \.(c|cc|cxx|cpp|cu|h|hpp|hxx)$
-        exclude: ^(mobile/|metal/|web/)
+        exclude: ^(mobile/) | ^(metal/) | ^(web/)
 #-   repo: local
     #hooks:
     #-   id: pylint-doc-string

mobile/src/io/ios_io/PaddleMobileCPU.h

@@ -139,6 +139,18 @@
  */
 - (PaddleMobileCPUResult *)predict:(CGImageRef)image dim:(NSArray<NSNumber *> *)dim means:(NSArray<NSNumber *> *)means scale:(float)scale;
 
+/**
+ @b 进行预测, means stds和 scale 为训练模型时的预处理参数, 如训练时没有做这些预处理则直接使用 predict, 每一个像素经过这样的预处理 (x + means) * scale, 其中 x 为像素值
+
+ @param image 输入图像
+ @param dim 输入维度
+ @param means 预处理中 means
+ @param stds 预处理中 stds
+ @param scale 预处理中 scale
+ @return 预测结果
+ */
+- (PaddleMobileCPUResult *)predict:(CGImageRef)image dim:(NSArray<NSNumber *> *)dim means:(NSArray<NSNumber *> *)means stds:(NSArray<NSNumber *> *)stds scale:(float)scale;
+
 /**
  @b 进行预测, 预处理 means 值为 0, scale 值为 1
 

mobile/src/io/ios_io/PaddleMobileCPU.mm

@@ -181,25 +181,22 @@ static std::mutex shared_mutex;
       for (int x = 0; x < wanted_input_width; ++x) {
         int in_row = (y * imageHeight) / wanted_input_height;
         int in_col = (x * imageWidth) / wanted_input_width;
-        const UInt8 *in_pixel = input + (in_row * imageWidth * imageChannels) + (in_col * imageChannels);
+        const UInt8 *in_pixel = input + (in_row * sourceRowBytes) + (in_col * imageChannels);
         float *out_pos = out_row + x;
-        if (c == 0) {
-          *out_pos = (in_pixel[c] - means[c].floatValue) * scale;
-        }else if (c == 1){
-          *out_pos = (in_pixel[c] - means[c].floatValue) * scale;
-        }else if (c == 2){
-          *out_pos = (in_pixel[c] - means[c].floatValue) * scale;
-        }
+        *out_pos = (in_pixel[2 - c] - means[c].floatValue) * scale;
       }
     }
   }
 
 }
 
--(void)preprocess:(const UInt8 *)input output:(float *)output imageWidth:(int)imageWidth imageHeight:(int)imageHeight imageChannels:(int)imageChannels means:(NSArray<NSNumber *> *)means scale:(float)scale dim:(std::vector<int64_t>)dim{
+-(void)preprocess:(const UInt8 *)input output:(float *)output bytesPerRow:(int)bytesPerRow imageWidth:(int)imageWidth imageHeight:(int)imageHeight imageChannels:(int)imageChannels means:(NSArray<NSNumber *> *)means stds:(NSArray<NSNumber *> *)stds scale:(float)scale dim:(std::vector<int64_t>)dim {
   if (means == nil) {
     means = @[@0, @0, @0];
   }
+  if (stds == nil) {
+    stds = @[@1, @1, @1];
+  }
 
   int wanted_input_width = dim[3];
   int wanted_input_height = dim[2];
@@ -212,15 +209,9 @@ static std::mutex shared_mutex;
       for (int x = 0; x < wanted_input_width; ++x) {
         int in_row = (y * imageHeight) / wanted_input_height;
         int in_col = (x * imageWidth) / wanted_input_width;
-        const UInt8 *in_pixel = input + (in_row * imageWidth * imageChannels) + (in_col * imageChannels);
+        const UInt8 *in_pixel = input + (in_row * bytesPerRow) + (in_col * imageChannels);
         float *out_pos = out_row + x;
-        if (c == 0) {
-          *out_pos = (in_pixel[c] - means[c].floatValue) * scale;
-        }else if (c == 1){
-          *out_pos = (in_pixel[c] - means[c].floatValue) * scale;
-        }else if (c == 2){
-          *out_pos = (in_pixel[c] - means[c].floatValue) * scale;
-        }
+        *out_pos = (in_pixel[2 - c] - means[c].floatValue) / stds[c].floatValue * scale;
       }
     }
   }
@@ -278,8 +269,7 @@ static std::mutex shared_mutex;
   return cpuResult;
 }
 
-- (PaddleMobileCPUResult *)predict:(CGImageRef)image dim:(NSArray<NSNumber *> *)dim means:(NSArray<NSNumber *> *)means scale:(float)scale{
-//  printf(" predict one ");
+- (PaddleMobileCPUResult *)predict:(CGImageRef)image dim:(NSArray<NSNumber *> *)dim means:(NSArray<NSNumber *> *)means stds:(NSArray<NSNumber *> *)stds scale:(float)scale {
   std::lock_guard<std::mutex> lock(shared_mutex);
   if (!loaded_) {
     printf("PaddleMobile doesn't be loaded yet");
@@ -310,7 +300,7 @@ static std::mutex shared_mutex;
 
   // sample image
   float *output = (float *)malloc(numel*sizeof(float));
-  [self preprocess:input output:output imageWidth:image_width imageHeight:image_height imageChannels:image_channels means:means scale:scale dim:dim_vec];
+  [self preprocess:input output:output bytesPerRow:sourceRowBytes imageWidth:image_width imageHeight:image_height imageChannels:image_channels means:means stds:stds scale:scale dim:dim_vec];
   float *dataPointer = nullptr;
   if (nullptr != output) {
     dataPointer = output;
@@ -351,7 +341,11 @@ static std::mutex shared_mutex;
 }
 
 - (PaddleMobileCPUResult *)predict:(CGImageRef)image dim:(NSArray<NSNumber *> *)dim {
-  return [self predict:image dim:dim means:nil scale:1];
+  return [self predict:image dim:dim means:nil stds:nil scale:1];
+}
+
+- (PaddleMobileCPUResult *)predict:(CGImageRef)image dim:(NSArray<NSNumber *> *)dim means:(NSArray<NSNumber *> *)means scale:(float)scale {
+  return [self predict:image dim:dim means:means stds:nil scale:scale];
 }
 
 - (PaddleMobileCPUResult *)fetchOutput{