// Copyright 2019 Nick White. // Use of this source code is governed by the GPLv3 // license that can be found in the LICENSE file. package preproc // TODO: add different pages as test cases // TODO: test non integral img version import ( "image" "image/draw" "image/png" "os" ) 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, img2 image.Image) 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 }