Use rgb2y instead of rgb2yuv

lib/pairwise_transform_jpeg.lua

@@ -43,8 +43,8 @@ function pairwise_transform.jpeg_(src, quality, size, offset, n, options)
       yc = iproc.byte2float(yc)
       if options.rgb then
       else
-	 yc = image.rgb2yuv(yc)[1]:reshape(1, yc:size(2), yc:size(3))
-	 xc = image.rgb2yuv(xc)[1]:reshape(1, xc:size(2), xc:size(3))
+	 yc = iproc.rgb2y(yc)
+	 xc = iproc.rgb2y(xc)
       end
       if torch.uniform() < options.nr_rate then
 	 -- reducing noise

lib/pairwise_transform_jpeg_scale.lua

@@ -118,8 +118,8 @@ function pairwise_transform.jpeg_scale(src, scale, style, noise_level, size, off
       yc = iproc.byte2float(yc)
       if options.rgb then
       else
-	 yc = image.rgb2yuv(yc)[1]:reshape(1, yc:size(2), yc:size(3))
-	 xc = image.rgb2yuv(xc)[1]:reshape(1, xc:size(2), xc:size(3))
+	 yc = iproc.rgb2y(yc)
+	 xc = iproc.rgb2y(xc)
       end
       table.insert(batch, {xc, iproc.crop(yc, offset, offset, size - offset, size - offset)})
    end

lib/pairwise_transform_scale.lua

@@ -51,8 +51,8 @@ function pairwise_transform.scale(src, scale, size, offset, n, options)
       yc = iproc.byte2float(yc)
       if options.rgb then
       else
-	 yc = image.rgb2yuv(yc)[1]:reshape(1, yc:size(2), yc:size(3))
-	 xc = image.rgb2yuv(xc)[1]:reshape(1, xc:size(2), xc:size(3))
+	 yc = iproc.rgb2y(yc)
+	 xc = iproc.rgb2y(xc)
       end
       table.insert(batch, {xc, iproc.crop(yc, offset, offset, size - offset, size - offset)})
    end