func main() {
defer common.LogPanic()
common.Init()
if flag.NArg() != 2 {
log.Fatal("Usage: imagediff [--out filename] imagepath1.png imagepath2.png\n")
}
a, err := diff.OpenImage(flag.Arg(0))
if err != nil {
log.Fatal(err)
}
b, err := diff.OpenImage(flag.Arg(1))
if err != nil {
log.Fatal(err)
}
metrics, d := diff.Diff(a, b)
fmt.Printf("Dimensions are different: %v\n", metrics.DimDiffer)
fmt.Printf("Number of pixels different: %v\n", metrics.NumDiffPixels)
fmt.Printf("Pixel diff percent: %v\n", metrics.PixelDiffPercent)
if *out == "" {
return
} else {
fmt.Println("Writing image diff.")
}
f, err := os.Create(*out)
if err != nil {
log.Fatal(err)
}
if err := png.Encode(f, d); err != nil {
log.Fatal(err)
}
}
// Calculate the DiffMetrics for the provided digests.
func (fs *FileDiffStore) diff(d1, d2 string) (*diff.DiffMetrics, error) {
img1, err := fs.getDigestImage(d1)
if err != nil {
return nil, err
}
img2, err := fs.getDigestImage(d2)
if err != nil {
return nil, err
}
dm, resultImg := diff.Diff(img1, img2)
baseName := getDiffBasename(d1, d2)
// Write the diff image to a temporary file.
tempOut, err := ioutil.TempFile(fs.localTempFileDir, fmt.Sprintf("tempfile-%s", baseName))
if err != nil {
return nil, fmt.Errorf("Unable to create temp file: %s", err)
}
encoder := png.Encoder{CompressionLevel: png.BestSpeed}
if err := encoder.Encode(tempOut, resultImg); err != nil {
return nil, err
}
err = tempOut.Close()
if err != nil {
return nil, fmt.Errorf("Error closing temp file: %s", err)
}
diffImageFilename := fmt.Sprintf("%s.%s", baseName, IMG_EXTENSION)
outputFileName, err := fs.createRadixPath(fs.localDiffDir, diffImageFilename)
if err != nil {
return nil, err
}
fs.diffDirLock.Lock()
defer fs.diffDirLock.Unlock()
if err := os.Rename(tempOut.Name(), outputFileName); err != nil {
return nil, fmt.Errorf("Unable to move file: %s", err)
}
// This sets a logical path for this file.
dm.PixelDiffFilePath = diffImageFilename
return dm, nil
}