Reorganise image manipulation to separate integral image parts

Also unify everything else under preproc/

Note that the UsefulImg interface should be used by the main
functions, to simplify things, but this hasn't been done yet.

1 files changed, 56 insertions, 0 deletions

diff --git a/preproc/helpers_test.go b/preproc/helpers_test.go
new file mode 100644
index 0000000..326b59d
--- /dev/null
+++ b/preproc/helpers_test.go
@@ -0,0 +1,56 @@
+package preproc
+
+// TODO: add different pages as test cases
+// TODO: test non integral img version
+
+import (
+	"flag"
+	"image"
+	"image/draw"
+	"image/png"
+	"os"
+)
+
+var update = flag.Bool("update", false, "update golden files")
+
+func decode(s string) (*image.Gray, error) {
+	f, err := os.Open(s)
+	defer f.Close()
+	if err != nil {
+		return nil, err
+	}
+	img, err := png.Decode(f)
+	if err != nil {
+		return nil, err
+	}
+	b := img.Bounds()
+	gray := image.NewGray(image.Rect(0, 0, b.Dx(), b.Dy()))
+	draw.Draw(gray, b, img, b.Min, draw.Src)
+	return gray, nil
+}
+
+func imgsequal(img1 *image.Gray, img2 *image.Gray) bool {
+	b := img1.Bounds()
+	if !b.Eq(img2.Bounds()) {
+		return false
+	}
+	for y := b.Min.Y; y < b.Max.Y; y++ {
+		for x := b.Min.X; x < b.Max.X; x++ {
+			r0, g0, b0, a0 := img1.At(x, y).RGBA()
+			r1, g1, b1, a1 := img2.At(x, y).RGBA()
+			if r0 != r1 {
+				return false
+			}
+			if g0 != g1 {
+				return false
+			}
+			if b0 != b1 {
+				return false
+			}
+			if a0 != a1 {
+				return false
+			}
+		}
+	}
+	return true
+}