Add cleanup mode to stitcher

bin/stitch/README.md

@@ -30,7 +30,8 @@ example list of files:
 - Or run the program with parameters:
   - `divide int`
     A downscaling factor. 2 will produce an image with half the side lengths. (default 1)
-  - `input string`The source path of the image tiles to be stitched. (default "..\\..\\output")
+  - `input string`
+    The source path of the image tiles to be stitched. (default "..\\..\\output")
   - `output string`
     The path and filename of the resulting stitched image. (default "output.png")
   - `xmax int`
@@ -43,13 +44,21 @@ example list of files:
     Upper bound of the output rectangle. This coordinate is included in the output.
   - `prerender`
     Pre renders the image in RAM before saving. Can speed things up if you have enough RAM.
+  - `cleanup float`
+    Enables cleanup mode with the given float as threshold. This will **DELETE** images from the input folder; no stitching will be done in this mode. A good value to start with is `0.999`, which deletes images where the sum of the min-max difference of each sub-pixel overlapping with other images is less than 99.9%% of the maximum possible sum of pixel differences.
 
 To output the 100x100 area that is centered at the origin use:
 
 ``` Shell Session
 ./stitch -divide 1 -xmin -50 -xmax 50 -ymin -50 -ymax 50
 ```
 
+To remove images that would cause artifacts (You should recapture the deleted images afterwards):
+
+``` Shell Session
+./stitch -cleanup 0.999
+```
+
 To enter the parameters inside of the program:
 
 ``` Shell Session

bin/stitch/imagetile.go

@@ -26,6 +26,8 @@ type imageTile struct {
 	image         image.Image   // Either a rectangle or an RGBA image. The bounds of this image are determined by the filename.
 	imageMutex    *sync.RWMutex //
 	imageUsedFlag bool          // Flag signalling, that the image was used recently
+
+	pixelErrorSum uint64 // Sum of the difference between the (sub)pixels of all overlapping images. 0 Means that all overlapping images are identical.
 }
 
 func (it *imageTile) GetImage() (*image.RGBA, error) {

bin/stitch/imagetiles.go

@@ -104,7 +104,7 @@ func Stitch(tiles []imageTile, destImage *image.RGBA) error {
 	return nil
 }
 
-// StitchGrid calls stitch, but divides the workload into a grid of chunks.
+// StitchGrid calls Stitch, but divides the workload into a grid of chunks.
 // Additionally it runs the workload multithreaded.
 func StitchGrid(tiles []imageTile, destImage *image.RGBA, gridSize int, bar *pb.ProgressBar) (errResult error) {
 	//workloads := gridifyRectangle(destImage.Bounds(), gridSize)
@@ -207,3 +207,124 @@ func drawMedianBlended(images []*image.RGBA, destImage *image.RGBA) {
 		}
 	}
 }
+
+// Compare takes a list of tiles and compares them pixel by pixel.
+// The resulting pixel difference sum is stored in each tile.
+func Compare(tiles []imageTile, bounds image.Rectangle) error {
+	intersectTiles := []*imageTile{}
+	images := []*image.RGBA{}
+
+	// Get only the tiles that intersect with the bounds.
+	// Ignore alignment here, doesn't matter if an image overlaps a few pixels anyways.
+	for i, tile := range tiles {
+		if tile.OffsetBounds().Overlaps(bounds) {
+			tilePtr := &tiles[i]
+			intersectTiles = append(intersectTiles, tilePtr)
+			img, err := tilePtr.GetImage()
+			if err != nil {
+				return fmt.Errorf("Couldn't get image: %w", err)
+			}
+			imgCopy := *img
+			imgCopy.Rect = imgCopy.Rect.Add(tile.offset).Inset(4) // Reduce image bounds by 4 pixels on each side, because otherwise there will be artifacts.
+			images = append(images, &imgCopy)
+		}
+	}
+
+	tempTilesEmpty := make([]*imageTile, 0, len(intersectTiles))
+
+	for iy := bounds.Min.Y; iy < bounds.Max.Y; iy++ {
+		for ix := bounds.Min.X; ix < bounds.Max.X; ix++ {
+			var rMin, rMax, gMin, gMax, bMin, bMax uint8
+			point := image.Point{ix, iy}
+			found := false
+			tempTiles := tempTilesEmpty
+
+			// Iterate through all images and find min and max subpixel values.
+			for i, img := range images {
+				if point.In(img.Bounds()) {
+					tempTiles = append(tempTiles, intersectTiles[i])
+					col := img.RGBAAt(point.X, point.Y)
+					if !found {
+						found = true
+						rMin, rMax, gMin, gMax, bMin, bMax = col.R, col.R, col.G, col.G, col.B, col.B
+					} else {
+						if rMin > col.R {
+							rMin = col.R
+						}
+						if rMax < col.R {
+							rMax = col.R
+						}
+						if gMin > col.G {
+							gMin = col.G
+						}
+						if gMax < col.G {
+							gMax = col.G
+						}
+						if bMin > col.B {
+							bMin = col.B
+						}
+						if bMax < col.B {
+							bMax = col.B
+						}
+					}
+				}
+			}
+
+			// If there were no images to get data from, ignore the pixel.
+			if !found {
+				continue
+			}
+
+			// Write the error value back into the tiles (Only those that contain the point point)
+			for _, tile := range tempTiles {
+				tile.pixelErrorSum += uint64(rMax-rMin) + uint64(gMax-gMin) + uint64(bMax-bMin)
+			}
+
+		}
+	}
+
+	return nil
+}
+
+// CompareGrid calls Compare, but divides the workload into a grid of chunks.
+// Additionally it runs the workload multithreaded.
+func CompareGrid(tiles []imageTile, bounds image.Rectangle, gridSize int, bar *pb.ProgressBar) (errResult error) {
+	//workloads := gridifyRectangle(destImage.Bounds(), gridSize)
+	workloads, err := hilbertifyRectangle(bounds, gridSize)
+	if err != nil {
+		return err
+	}
+
+	if bar != nil {
+		bar.SetTotal(int64(len(workloads))).Start()
+	}
+
+	// Start worker threads
+	wc := make(chan image.Rectangle)
+	wg := sync.WaitGroup{}
+	for i := 0; i < runtime.NumCPU()*2; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for workload := range wc {
+				if err := Compare(tiles, workload); err != nil {
+					errResult = err // This will not stop execution, but at least one of any errors is returned.
+				}
+				if bar != nil {
+					bar.Increment()
+				}
+			}
+		}()
+	}
+
+	// Push workload to worker threads
+	for _, workload := range workloads {
+		wc <- workload
+	}
+
+	// Wait until all worker threads are done
+	close(wc)
+	wg.Wait()
+
+	return
+}

bin/stitch/stitch.go

@@ -28,6 +28,7 @@ var flagYMin = flag.Int("ymin", 0, "Upper bound of the output rectangle. This co
 var flagXMax = flag.Int("xmax", 0, "Right bound of the output rectangle. This coordinate is not included in the output.")
 var flagYMax = flag.Int("ymax", 0, "Lower bound of the output rectangle. This coordinate is not included in the output.")
 var flagPrerender = flag.Bool("prerender", false, "Pre renders the image in RAM before saving. Can speed things up if you have enough RAM.")
+var flagCleanupThreshold = flag.Float64("cleanup", 0, "Enable cleanup mode with the given threshold. This will DELETE images from the input folder, no stitching will be done in this mode. A good value to start with is 0.999, which deletes images where the sum of the min-max difference of each sub-pixel overlapping with other images is less than 99.9%% of the maximum possible sum of pixel differences.")
 
 func main() {
 	flag.Parse()
@@ -142,6 +143,63 @@ func main() {
 		outputRect = image.Rect(xMin, yMin, xMax, yMax)
 	}
 
+	// Query the user, if there were no cmd arguments given
+	/*if flag.NFlag() == 0 {
+		fmt.Println("\nYou can now define a cleanup threshold. This mode will DELETE input images based on their similarity with other overlapping input images. The range is from 0, where no images are deleted, to 1 where all images will be deleted. A good value to get rid of most artifacts is 0.999. If you enter a threshold above 0, the program will not stitch, but DELETE some of your input images. If you want to stitch, enter 0.")
+		prompt := promptui.Prompt{
+			Label:     "Enter cleanup threshold:",
+			Default:   strconv.FormatFloat(*flagCleanupThreshold, 'f', -1, 64),
+			AllowEdit: true,
+			Validate: func(s string) error {
+				result, err := strconv.ParseFloat(s, 64)
+				if err != nil {
+					return err
+				}
+
+				if result < 0 || result > 1 {
+					return fmt.Errorf("Number %v outside of valid range [0;1]", result)
+				}
+
+				return nil
+			},
+		}
+
+		result, err := prompt.Run()
+		if err != nil {
+			log.Panicf("Error while getting user input: %v", err)
+		}
+		*flagCleanupThreshold, err = strconv.ParseFloat(result, 64)
+		if err != nil {
+			log.Panicf("Error while parsing user input: %v", err)
+		}
+	}*/
+
+	if *flagCleanupThreshold < 0 || *flagCleanupThreshold > 1 {
+		log.Panicf("Cleanup threshold (%v) outside of valid range [0;1]", *flagCleanupThreshold)
+	}
+	if *flagCleanupThreshold > 0 {
+		bar := pb.Full.New(0)
+
+		log.Printf("Cleaning up %v tiles at %v", len(tiles), outputRect)
+		if err := CompareGrid(tiles, outputRect, 512, bar); err != nil {
+			log.Panic(err)
+		}
+		bar.Finish()
+
+		for _, tile := range tiles {
+			pixelErrorSumNormalized := float64(tile.pixelErrorSum) / float64(tile.Bounds().Size().X*tile.Bounds().Size().Y*3*255)
+			if 1-pixelErrorSumNormalized <= *flagCleanupThreshold {
+				os.Remove(tile.fileName)
+				log.Printf("Tile %v has matching factor of %f. Deleted file!", &tile, 1-pixelErrorSumNormalized)
+			} else {
+				log.Printf("Tile %v has matching factor of %f", &tile, 1-pixelErrorSumNormalized)
+			}
+
+		}
+
+		return
+	}
+
 	// Query the user, if there were no cmd arguments given
 	if flag.NFlag() == 0 {
 		prompt := promptui.Prompt{