libwebp-0.6.0-rc1

third_party/libwebp/enc/picture_psnr_enc.c

+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// WebPPicture tools for measuring distortion
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <math.h>
+#include <stdlib.h>
+
+#include "./vp8i_enc.h"
+#include "../utils/utils.h"
+
+typedef double (*AccumulateFunc)(const uint8_t* src, int src_stride,
+                                 const uint8_t* ref, int ref_stride,
+                                 int w, int h);
+
+//------------------------------------------------------------------------------
+// local-min distortion
+//
+// For every pixel in the *reference* picture, we search for the local best
+// match in the compressed image. This is not a symmetrical measure.
+
+#define RADIUS 2  // search radius. Shouldn't be too large.
+
+static double AccumulateLSIM(const uint8_t* src, int src_stride,
+                             const uint8_t* ref, int ref_stride,
+                             int w, int h) {
+  int x, y;
+  double total_sse = 0.;
+  for (y = 0; y < h; ++y) {
+    const int y_0 = (y - RADIUS < 0) ? 0 : y - RADIUS;
+    const int y_1 = (y + RADIUS + 1 >= h) ? h : y + RADIUS + 1;
+    for (x = 0; x < w; ++x) {
+      const int x_0 = (x - RADIUS < 0) ? 0 : x - RADIUS;
+      const int x_1 = (x + RADIUS + 1 >= w) ? w : x + RADIUS + 1;
+      double best_sse = 255. * 255.;
+      const double value = (double)ref[y * ref_stride + x];
+      int i, j;
+      for (j = y_0; j < y_1; ++j) {
+        const uint8_t* const s = src + j * src_stride;
+        for (i = x_0; i < x_1; ++i) {
+          const double diff = s[i] - value;
+          const double sse = diff * diff;
+          if (sse < best_sse) best_sse = sse;
+        }
+      }
+      total_sse += best_sse;
+    }
+  }
+  return total_sse;
+}
+#undef RADIUS
+
+static double AccumulateSSE(const uint8_t* src, int src_stride,
+                            const uint8_t* ref, int ref_stride,
+                            int w, int h) {
+  int y;
+  double total_sse = 0.;
+  for (y = 0; y < h; ++y) {
+    total_sse += VP8AccumulateSSE(src, ref, w);
+    src += src_stride;
+    ref += ref_stride;
+  }
+  return total_sse;
+}
+
+//------------------------------------------------------------------------------
+
+static double AccumulateSSIM(const uint8_t* src, int src_stride,
+                             const uint8_t* ref, int ref_stride,
+                             int w, int h) {
+  const int w0 = (w < VP8_SSIM_KERNEL) ? w : VP8_SSIM_KERNEL;
+  const int w1 = w - VP8_SSIM_KERNEL - 1;
+  const int h0 = (h < VP8_SSIM_KERNEL) ? h : VP8_SSIM_KERNEL;
+  const int h1 = h - VP8_SSIM_KERNEL - 1;
+  int x, y;
+  double sum = 0.;
+  for (y = 0; y < h0; ++y) {
+    for (x = 0; x < w; ++x) {
+      sum += VP8SSIMGetClipped(src, src_stride, ref, ref_stride, x, y, w, h);
+    }
+  }
+  for (; y < h1; ++y) {
+    for (x = 0; x < w0; ++x) {
+      sum += VP8SSIMGetClipped(src, src_stride, ref, ref_stride, x, y, w, h);
+    }
+    for (; x < w1; ++x) {
+      const int off1 = x - VP8_SSIM_KERNEL + (y - VP8_SSIM_KERNEL) * src_stride;
+      const int off2 = x - VP8_SSIM_KERNEL + (y - VP8_SSIM_KERNEL) * ref_stride;
+      sum += VP8SSIMGet(src + off1, src_stride, ref + off2, ref_stride);
+    }
+    for (; x < w; ++x) {
+      sum += VP8SSIMGetClipped(src, src_stride, ref, ref_stride, x, y, w, h);
+    }
+  }
+  for (; y < h; ++y) {
+    for (x = 0; x < w; ++x) {
+      sum += VP8SSIMGetClipped(src, src_stride, ref, ref_stride, x, y, w, h);
+    }
+  }
+  return sum;
+}
+
+//------------------------------------------------------------------------------
+// Distortion
+
+// Max value returned in case of exact similarity.
+static const double kMinDistortion_dB = 99.;
+
+static double GetPSNR(double v, double size) {
+  return (v > 0. && size > 0.) ? -4.3429448 * log(v / (size * 255 * 255.))
+                               : kMinDistortion_dB;
+}
+
+static double GetLogSSIM(double v, double size) {
+  v = (size > 0.) ? v / size : 1.;
+  return (v < 1.) ? -10.0 * log10(1. - v) : kMinDistortion_dB;
+}
+
+int WebPPlaneDistortion(const uint8_t* src, size_t src_stride,
+                        const uint8_t* ref, size_t ref_stride,
+                        int width, int height, size_t x_step,
+                        int type, float* distortion, float* result) {
+  uint8_t* allocated = NULL;
+  const AccumulateFunc metric = (type == 0) ? AccumulateSSE :
+                                (type == 1) ? AccumulateSSIM :
+                                              AccumulateLSIM;
+  if (src == NULL || ref == NULL ||
+      src_stride < x_step * width || ref_stride < x_step * width ||
+      result == NULL || distortion == NULL) {
+    return 0;
+  }
+
+  VP8SSIMDspInit();
+  if (x_step != 1) {   // extract a packed plane if needed
+    int x, y;
+    uint8_t* tmp1;
+    uint8_t* tmp2;
+    allocated =
+        (uint8_t*)WebPSafeMalloc(2ULL * width * height, sizeof(*allocated));
+    if (allocated == NULL) return 0;
+    tmp1 = allocated;
+    tmp2 = tmp1 + (size_t)width * height;
+    for (y = 0; y < height; ++y) {
+      for (x = 0; x < width; ++x) {
+        tmp1[x + y * width] = src[x * x_step + y * src_stride];
+        tmp2[x + y * width] = ref[x * x_step + y * ref_stride];
+      }
+    }
+    src = tmp1;
+    ref = tmp2;
+  }
+  *distortion = (float)metric(src, width, ref, width, width, height);
+  WebPSafeFree(allocated);
+
+  *result = (type == 1) ? (float)GetLogSSIM(*distortion, (double)width * height)
+                        : (float)GetPSNR(*distortion, (double)width * height);
+  return 1;
+}
+
+int WebPPictureDistortion(const WebPPicture* src, const WebPPicture* ref,
+                          int type, float results[5]) {
+  int w, h, c;
+  int ok = 0;
+  WebPPicture p0, p1;
+  double total_size = 0., total_distortion = 0.;
+  if (src == NULL || ref == NULL ||
+      src->width != ref->width || src->height != ref->height ||
+      results == NULL) {
+    return 0;
+  }
+
+  VP8SSIMDspInit();
+  if (!WebPPictureInit(&p0) || !WebPPictureInit(&p1)) return 0;
+  w = src->width;
+  h = src->height;
+  if (!WebPPictureView(src, 0, 0, w, h, &p0)) goto Error;
+  if (!WebPPictureView(ref, 0, 0, w, h, &p1)) goto Error;
+
+  // We always measure distortion in ARGB space.
+  if (p0.use_argb == 0 && !WebPPictureYUVAToARGB(&p0)) goto Error;
+  if (p1.use_argb == 0 && !WebPPictureYUVAToARGB(&p1)) goto Error;
+  for (c = 0; c < 4; ++c) {
+    float distortion;
+    const size_t stride0 = 4 * (size_t)p0.argb_stride;
+    const size_t stride1 = 4 * (size_t)p1.argb_stride;
+    if (!WebPPlaneDistortion((const uint8_t*)p0.argb + c, stride0,
+                             (const uint8_t*)p1.argb + c, stride1,
+                             w, h, 4, type, &distortion, results + c)) {
+      goto Error;
+    }
+    total_distortion += distortion;
+    total_size += w * h;
+  }
+
+  results[4] = (type == 1) ? (float)GetLogSSIM(total_distortion, total_size)
+                           : (float)GetPSNR(total_distortion, total_size);
+  ok = 1;
+
+ Error:
+  WebPPictureFree(&p0);
+  WebPPictureFree(&p1);
+  return ok;
+}
+
+//------------------------------------------------------------------------------