Experimental: OpenMP

Makefile

@@ -63,6 +63,10 @@ install-coverage:
 	CFLAGS="-coverage" python setup.py build_ext install
 	python selftest.py --installed
 
+install-openmp:
+	python setup.py build_ext --enable-openmp install
+	python selftest.py --installed
+
 debug:
 # make a debug version if we don't have a -dbg python. Leaves in symbols
 # for our stuff, kills optimization, and redirects to dev null so we

Tests/mpbench.py

@@ -0,0 +1,36 @@
+from PIL import Image
+import time
+import math
+
+def timeit(n, f, *args, **kwargs):
+    def run():
+        start = time.time()
+        f(*args, **kwargs)
+        return time.time() - start
+
+    runs = [run() for _ in range(n)]
+    mean = sum(runs)/float(n)
+    stddev = math.sqrt(sum((r-mean)**2 for r in runs)/float(n))
+    return {'mean':mean,
+            'median': sorted(runs)[int(n/2)],
+            'min': min(runs),
+            'max': max(runs),
+            'stddev':stddev,
+            'dev_pct': stddev/mean*100.0
+            }
+
+    #return min(run() for _ in range(n))
+
+n = 400
+image = Image.open('5k_image.jpg').copy()
+print 'warmup {mean:.4}'.format(**timeit(n // 4, image.im.resize, (2048, 1152), Image.ANTIALIAS))
+print "%s runs"%n
+print "Interpolation | Size  |  min  |  max  |  mean | median| stddev | Dev %"
+print "--------- | --------- | ----- | ----- | ----- | ----- | -----  | ----"
+print 'Antialias | 2048x1152 | {min:5.3f} | {max:5.3f} | {mean:5.3f} | {median:5.3f} | {stddev:5.4f} | {dev_pct:4.1f}%'.format(**timeit(n, image.im.resize, (2048, 1152), Image.ANTIALIAS))
+print 'Antialias | 320x240   | {min:5.3f} | {max:5.3f} | {mean:5.3f} | {median:5.3f} | {stddev:5.4f} | {dev_pct:4.1f}%'.format(**timeit(n, image.im.resize, (320, 240),   Image.ANTIALIAS))
+print 'Bicubic   | 2048x1152 | {min:5.3f} | {max:5.3f} | {mean:5.3f} | {median:5.3f} | {stddev:5.4f} | {dev_pct:4.1f}%'.format(**timeit(n, image.im.resize, (2048, 1152), Image.BICUBIC))
+print 'Bicubic   | 320x240   | {min:5.3f} | {max:5.3f} | {mean:5.3f} | {median:5.3f} | {stddev:5.4f} | {dev_pct:4.1f}%'.format(**timeit(n, image.im.resize, (320, 240),   Image.BICUBIC))
+print 'Bilinear  | 2048x1152 | {min:5.3f} | {max:5.3f} | {mean:5.3f} | {median:5.3f} | {stddev:5.4f} | {dev_pct:4.1f}%'.format(**timeit(n, image.im.resize, (2048, 1152), Image.BILINEAR))
+print 'Bilinear  | 320x240   | {min:5.3f} | {max:5.3f} | {mean:5.3f} | {median:5.3f} | {stddev:5.4f} | {dev_pct:4.1f}%'.format(**timeit(n, image.im.resize, (320, 240),   Image.BILINEAR))
+

libImaging/Geometry.c

@@ -5,6 +5,7 @@
    Rotating in chunks that fit in the cache can speed up rotation
    8x on a modern CPU. A chunk size of 128 requires only 65k and is large enough
    that the overhead from the extra loops are not apparent. */
+
 #define ROTATE_CHUNK 512
 #define ROTATE_SMALL_CHUNK 8
 
@@ -163,11 +164,13 @@ ImagingTranspose(Imaging imOut, Imaging imIn)
 
     ImagingSectionEnter(&cookie);
 
-    if (imIn->image8)
+    if (imIn->image8){
+#pragma omp parallel for private(x,y,xx,yy,xxx,yyy,yysize,xxsize,xxxsize,yyysize) shared(imIn,imOut) default(none) collapse(2)
         TRANSPOSE(UINT8, image8)
-    else
+    } else {
+#pragma omp parallel for private(x,y,xx,yy,xxx,yyy,yysize,xxsize,xxxsize,yyysize) shared(imIn,imOut) default(none) collapse(2)
         TRANSPOSE(INT32, image32)
-
+    }
     ImagingSectionLeave(&cookie);
 
 #undef TRANSPOSE

libImaging/Resample.c

@@ -241,9 +241,10 @@ ImagingResampleHorizontal_8bpc(Imaging imOut, Imaging imIn, int offset,
 
     ImagingSectionEnter(&cookie);
     if (imIn->image8) {
+#pragma omp parallel for private(k,x,xx,yy,xmin,xmax,ss0,ss1,ss2,ss3) shared(imIn,imOut,kk,ksize,bounds,offset) default(none) collapse(2)
         for (yy = 0; yy < imOut->ysize; yy++) {
             for (xx = 0; xx < imOut->xsize; xx++) {
-                xmin = bounds[xx * 2 + 0];
+	        xmin = bounds[xx * 2 + 0];
                 xmax = bounds[xx * 2 + 1];
                 k = &kk[xx * ksize];
                 ss0 = 1 << (PRECISION_BITS -1);
@@ -254,7 +255,8 @@ ImagingResampleHorizontal_8bpc(Imaging imOut, Imaging imIn, int offset,
         }
     } else if (imIn->type == IMAGING_TYPE_UINT8) {
         if (imIn->bands == 2) {
-            for (yy = 0; yy < imOut->ysize; yy++) {
+#pragma omp parallel for private(k,x,xx,yy,xmin,xmax,ss0,ss1,ss2,ss3) shared(imIn,imOut,kk,ksize,bounds,offset) default(none) collapse(2)
+	    for (yy = 0; yy < imOut->ysize; yy++) {
                 for (xx = 0; xx < imOut->xsize; xx++) {
                     xmin = bounds[xx * 2 + 0];
                     xmax = bounds[xx * 2 + 1];
@@ -269,7 +271,8 @@ ImagingResampleHorizontal_8bpc(Imaging imOut, Imaging imIn, int offset,
                 }
             }
         } else if (imIn->bands == 3) {
-            for (yy = 0; yy < imOut->ysize; yy++) {
+#pragma omp parallel for private(k,x,xx,yy,xmin,xmax,ss0,ss1,ss2,ss3) shared(imIn,imOut,kk,ksize,bounds,offset) default(none) collapse(2)
+	    for (yy = 0; yy < imOut->ysize; yy++) {
                 for (xx = 0; xx < imOut->xsize; xx++) {
                     xmin = bounds[xx * 2 + 0];
                     xmax = bounds[xx * 2 + 1];
@@ -285,6 +288,7 @@ ImagingResampleHorizontal_8bpc(Imaging imOut, Imaging imIn, int offset,
                 }
             }
         } else {
+#pragma omp parallel for private(k,x,xx,yy,xmin,xmax,ss0,ss1,ss2,ss3) shared(imIn,imOut,kk,ksize,bounds,offset) default(none) collapse(2)
             for (yy = 0; yy < imOut->ysize; yy++) {
                 for (xx = 0; xx < imOut->xsize; xx++) {
                     xmin = bounds[xx * 2 + 0];
@@ -322,7 +326,8 @@ ImagingResampleVertical_8bpc(Imaging imOut, Imaging imIn, int offset,
 
     ImagingSectionEnter(&cookie);
     if (imIn->image8) {
-        for (yy = 0; yy < imOut->ysize; yy++) {
+#pragma omp parallel for private(k,y,xx,yy,ymin,ymax,ss0,ss1,ss2,ss3) shared(imIn,imOut,kk,ksize,bounds) default(none) 
+      for (yy = 0; yy < imOut->ysize; yy++) {
             k = &kk[yy * ksize];
             ymin = bounds[yy * 2 + 0];
             ymax = bounds[yy * 2 + 1];
@@ -335,6 +340,7 @@ ImagingResampleVertical_8bpc(Imaging imOut, Imaging imIn, int offset,
         }
     } else if (imIn->type == IMAGING_TYPE_UINT8) {
         if (imIn->bands == 2) {
+#pragma omp parallel for private(k,y,xx,yy,ymin,ymax,ss0,ss1,ss2,ss3) shared(imIn,imOut,kk,ksize,bounds) default(none) 
             for (yy = 0; yy < imOut->ysize; yy++) {
                 k = &kk[yy * ksize];
                 ymin = bounds[yy * 2 + 0];
@@ -350,6 +356,7 @@ ImagingResampleVertical_8bpc(Imaging imOut, Imaging imIn, int offset,
                 }
             }
         } else if (imIn->bands == 3) {
+#pragma omp parallel for private(k,y,xx,yy,ymin,ymax,ss0,ss1,ss2,ss3) shared(imIn,imOut,kk,ksize,bounds) default(none) 
             for (yy = 0; yy < imOut->ysize; yy++) {
                 k = &kk[yy * ksize];
                 ymin = bounds[yy * 2 + 0];
@@ -366,6 +373,7 @@ ImagingResampleVertical_8bpc(Imaging imOut, Imaging imIn, int offset,
                 }
             }
         } else {
+#pragma omp parallel for private(k,y,xx,yy,ymin,ymax,ss0,ss1,ss2,ss3) shared(imIn,imOut,kk,ksize,bounds) default(none) 
             for (yy = 0; yy < imOut->ysize; yy++) {
                 k = &kk[yy * ksize];
                 ymin = bounds[yy * 2 + 0];

setup.py

@@ -141,7 +141,7 @@ def _pkg_config(name):
 class pil_build_ext(build_ext):
     class feature:
         features = ['zlib', 'jpeg', 'tiff', 'freetype', 'raqm', 'lcms', 'webp',
-                    'webpmux', 'jpeg2000', 'imagequant']
+                    'webpmux', 'jpeg2000', 'imagequant', 'openmp']
 
         required = {'jpeg', 'zlib'}
 
@@ -179,9 +179,6 @@ def initialize_options(self):
 
     def finalize_options(self):
         build_ext.finalize_options(self)
-        if self.debug:
-            global DEBUG
-            DEBUG = True
         for x in self.feature:
             if getattr(self, 'disable_%s' % x):
                 setattr(self.feature, x, False)
@@ -199,7 +196,8 @@ def build_extensions(self):
 
         library_dirs = []
         include_dirs = []
-
+        extra_compile_args = []
+
         _add_directory(include_dirs, "libImaging")
 
         pkg_config = None
@@ -571,6 +569,10 @@ def build_extensions(self):
                         _find_library_file(self, "libwebpdemux")):
                     feature.webpmux = "libwebpmux"
 
+        if feature.require('openmp'):
+            extra_compile_args.append('-fopenmp')
+            feature.openmp = 'gomp'
+
         for f in feature:
             if not getattr(feature, f) and feature.require(f):
                 if f in ('jpeg', 'zlib'):
@@ -609,6 +611,8 @@ def build_extensions(self):
             libs.extend(["kernel32", "user32", "gdi32"])
         if struct.unpack("h", "\0\1".encode('ascii'))[0] == 1:
             defs.append(("WORDS_BIGENDIAN", None))
+        if feature.openmp:
+            libs.append(feature.openmp)
 
         if sys.platform == "win32" and not (PLATFORM_PYPY or PLATFORM_MINGW):
             defs.append(("PILLOW_VERSION", '"\\"%s\\""'%PILLOW_VERSION))
@@ -618,7 +622,8 @@ def build_extensions(self):
         exts = [(Extension("PIL._imaging",
                            files,
                            libraries=libs,
-                           define_macros=defs))]
+                           define_macros=defs,
+                           extra_compile_args=extra_compile_args))]
 
         #
         # additional libraries
@@ -697,7 +702,8 @@ def summary_report(self, feature):
             (feature.lcms, "LITTLECMS2"),
             (feature.webp, "WEBP"),
             (feature.webpmux, "WEBPMUX"),
-        ]
+            (feature.openmp, "OpenMP"),
+            ]
 
         all = 1
         for option in options: