add padding function to imgScalePadding()

src/interface.jl

@@ -2,7 +2,7 @@ module interface
 
 export np2juliaImage, juliaImg2npImg, imgScalePadding, url_to_image
 
-using Images, Colors, FileIO, HTTP
+using Images, Colors, FileIO, HTTP, NNlib
 # using Luxor
 
 using CondaPkg; CondaPkg.add_pip("pybase64"); CondaPkg.add_pip("opencv-python"); CondaPkg.add_pip("scikit-image"); CondaPkg.add_pip("Pillow"); CondaPkg.add_pip("numpy");
@@ -115,19 +115,31 @@ end
 #------------------------------------------------------------------------------------------------100
 
 """
-    Scale image to 1 specific dimension with padding. The longest side of an image will be used as
-    primary dimension.
+    Scale image to 1 specific dimension with or without padding. The longest side of an image will 
+    be used as primary dimension. If padding, final image dimension is (dimension x dimension)
+
+    Padding options:
+        :buttomRight    will place an image at top-left of a frame(dimension x dimension) and fill
+                        the rest of the frame with RGB(0,0,0)
 """
-function imgScalePadding(img::T, dimension::Integer, paddingType=nothing) where T <:DenseMatrix{RGB{N0f8}}
-    w, h = size(img)    # width = horizonal length, high = vertical length
+function imgScalePadding(img::T, dimension::Integer, paddingType::Symbol=:none) where T <:DenseMatrix{RGB{N0f8}}
+    h, w = size(img)    # high = vertical length, width = horizonal length
     primaryDimension = w > h ? w : h
-    dim = primaryDimension == w ? 1 : 2
 
-    percentage_scale = dimension / size(img)[dim];
+    percentage_scale = dimension / primaryDimension;
     new_size = trunc.(Int, size(img) .* percentage_scale);
-    img_rescaled = imresize(img, new_size);
+    img_resized = imresize(img, new_size);
 
-    return img_rescaled
+    h, w = size(img_resized)
+    if paddingType == :none
+        final_img = img_resized
+    elseif paddingType == :buttomRight  # image is at top-left of the frame, fill the rest
+        final_img = NNlib.pad_constant(img_resized, (0, dimension-h, 0, dimension-w), RGB(0,0,0))
+    else
+        error("undefined condition line $(@__LINE__)")
+    end
+
+    return final_img
 end