Changeset 32724 for trunk/psLib/src/imageops/psImageConvolve.c

Timestamp:

Nov 20, 2011, 2:24:57 PM (14 years ago)

Author:

eugene

Message:

creating psImageSmooth_PreAlloc_F32 to avoid excessive allocs

File:

• trunk/psLib/src/imageops/psImageConvolve.c (modified) (1 diff)

trunk/psLib/src/imageops/psImageConvolve.c

@@ -765 +765 @@
 }
 
+// XXX NOTE : work to do : figure out the actual containers needed in there, pre-allocate them
+bool psImageSmooth_PreAlloc_F32(psImage *image, double sigma, double Nsigma)
+{
+    PS_ASSERT_IMAGE_NON_NULL(image, NULL);
+    // assert on data type
+
+    // relevant terms
+    int Nrange = sigma*Nsigma + 0.5;    // Number of pixels either side for convolution kernel
+    int Nx = image->numCols;            // Number of columns
+    int Ny = image->numRows;            // Number of rows
+
+    IMAGE_SMOOTH_GAUSS(gaussnorm, Nrange, sigma, F32);
+    psF32 *gauss = &gaussnorm->data.F32[Nrange];
+       
+    // use a temp running buffer for X and Y directions.
+    psF32 *resultX = (psF32 *) psAlloc(Nx * sizeof(psF32));
+    memset (resultX, 0, Nx*sizeof(psF32));
+    psF32 *resultY = (psF32 *) psAlloc(Ny * sizeof(psF32));
+    memset (resultY, 0, Ny*sizeof(psF32));
+
+    /* Smooth in X direction */
+    {
+        for (int j = 0; j < Ny; j++) {
+            psF32 *vi = image->data.F32[j];
+            int xMax = PS_MIN(Nrange, Nx);
+            int convRange = PS_MIN(Nrange + 1, Nx);
+            /* Smooth first Nrange pixels, with renorm */
+            for (int i = 0; i < xMax; i++, vi++) {
+                psF32 *vr = vi - i;
+                psF32 *vg = gauss - i;
+                double g = 0.0;
+                double s = 0.0;
+                for (int n = -i; n < convRange; n++, vr++, vg++) {
+                    s += *vg * *vr;
+                    g += *vg;
+                }
+                resultX[i] = s / g;
+            }
+            /* If that's all the pixels we have, then we're done already */
+            if (Nx > Nrange) {
+                /* Smooth middle pixels */
+                for (int i = Nrange; i < Nx - Nrange; i++, vi++) {
+                    psF32 *vr = vi - Nrange;
+                    psF32 *vg = gauss - Nrange;
+                    double s = 0;
+                    for (int n = -Nrange; n < Nrange + 1; n++, vr++, vg++) {
+                        s += *vg * *vr;
+                    }
+                    resultX[i] = s;
+                }
+                /* Smooth last Nrange pixels, with renorm */
+                for (int i = Nx - Nrange; i < Nx; i++, vi++) {
+                    psF32 *vr = vi - Nrange;
+                    psF32 *vg = gauss - Nrange;
+                    double g = 0.0;
+                    double s = 0.0;
+                    for (int n = -Nrange; n < Nx - i; n++, vr++, vg++) {
+                        s += *vg * *vr;
+                        g += *vg;
+                    }
+                    resultX[i] = s / g;
+                }
+            }
+            memcpy(image->data.F32[j], resultX, Nx*sizeof(psF32));
+        }
+    }
+       
+    // this section probably hits the cache poorly for large images, but is probably OK for small ones
+    /* Smooth in Y direction */
+    {
+        for (int i = 0; i < Nx; i++) {
+            int yMax = PS_MIN(Nrange, Ny);
+            int convRange = PS_MIN(Nrange + 1, Ny);
+            /* Smooth first Nrange pixels, with renorm */
+            for (int j = 0; j < yMax; j++) {
+                psF32 *vg = gauss - j;
+                double g = 0.0;
+                double s = 0.0;
+                for (int n = -j; n < convRange; n++, vg++) {
+                    psF32 vr = image->data.F32[j+n][i];
+                    s += *vg * vr;
+                    g += *vg;
+                }
+                resultY[j] = s / g;
+            }
+            /* If that's all the pixels we have, then we're done already */
+            if (Ny > Nrange) {
+                /* Smooth middle pixels */
+                for (int j = Nrange; j < Ny - Nrange; j++) {
+                    psF32 *vg = gauss - Nrange;
+                    double s = 0;
+                    for (int n = -Nrange; n < Nrange + 1; n++, vg++) {
+                        psF32 vr = image->data.F32[j+n][i]; 
+                        s += *vg * vr;
+                    }
+                    resultY[j] = s;
+                }
+                /* Smooth last Nrange pixels, with renorm */
+                for (int j = Ny - Nrange; j < Ny; j++) {
+                    psF32 *vg = gauss - Nrange;
+                    double g = 0.0;
+                    double s = 0.0;
+                    for (int n = -Nrange; n < Ny - j; n++, vg++) {
+                        psF32 vr = image->data.F32[j+n][i];
+                        s += *vg * vr;
+                        g += *vg;
+                    }
+                    resultY[j] = s / g;
+                }
+            }
+            // loop here 
+            for (int j = 0; j < Ny; j++) {
+                image->data.F32[j][i] = resultY[j];
+            }
+        }
+    }
+       
+    psFree(resultX);
+    psFree(resultY);
+    psFree(gaussnorm);
+
+    return true;
+}
+
 static bool imageSmoothMaskPixels(psVector *out, const psImage *image, const psImage *mask,
                                   psImageMaskType maskVal, const psVector *x, const psVector *y,