Support I mode for BuiltinFilter

Tests/test_image_filter.py

@@ -30,15 +30,16 @@ from .helper import assert_image_equal, hopper
         ImageFilter.UnsharpMask(10),
     ),
 )
-@pytest.mark.parametrize("mode", ("L", "RGB", "CMYK"))
+@pytest.mark.parametrize("mode", ("L", "I", "RGB", "CMYK"))
 def test_sanity(filter_to_apply, mode):
     im = hopper(mode)
+    if mode != "I" or isinstance(filter_to_apply, ImageFilter.BuiltinFilter):
         out = im.filter(filter_to_apply)
         assert out.mode == im.mode
         assert out.size == im.size
 
 
-@pytest.mark.parametrize("mode", ("L", "RGB", "CMYK"))
+@pytest.mark.parametrize("mode", ("L", "I", "RGB", "CMYK"))
 def test_sanity_error(mode):
     with pytest.raises(TypeError):
         im = hopper(mode)
@@ -130,10 +131,12 @@ def test_kernel_not_enough_coefficients():
         ImageFilter.Kernel((3, 3), (0, 0))
 
 
-@pytest.mark.parametrize("mode", ("L", "LA", "RGB", "CMYK"))
+@pytest.mark.parametrize("mode", ("L", "LA", "I", "RGB", "CMYK"))
 def test_consistency_3x3(mode):
     with Image.open("Tests/images/hopper.bmp") as source:
-        with Image.open("Tests/images/hopper_emboss.bmp") as reference:
+        reference_name = "hopper_emboss"
+        reference_name += "_I.png" if mode == "I" else ".bmp"
+        with Image.open("Tests/images/" + reference_name) as reference:
             kernel = ImageFilter.Kernel(
                 (3, 3),
                 # fmt: off
@@ -146,16 +149,20 @@ def test_consistency_3x3(mode):
             source = source.split() * 2
             reference = reference.split() * 2
 
-            assert_image_equal(
+            if mode == "I":
-                Image.merge(mode, source[: len(mode)]).filter(kernel),
+                source = source[0].convert(mode)
-                Image.merge(mode, reference[: len(mode)]),
+            else:
-            )
+                source = Image.merge(mode, source[: len(mode)])
+            reference = Image.merge(mode, reference[: len(mode)])
+            assert_image_equal(source.filter(kernel), reference)
 
 
-@pytest.mark.parametrize("mode", ("L", "LA", "RGB", "CMYK"))
+@pytest.mark.parametrize("mode", ("L", "LA", "I", "RGB", "CMYK"))
 def test_consistency_5x5(mode):
     with Image.open("Tests/images/hopper.bmp") as source:
-        with Image.open("Tests/images/hopper_emboss_more.bmp") as reference:
+        reference_name = "hopper_emboss_more"
+        reference_name += "_I.png" if mode == "I" else ".bmp"
+        with Image.open("Tests/images/" + reference_name) as reference:
             kernel = ImageFilter.Kernel(
                 (5, 5),
                 # fmt: off
@@ -170,10 +177,12 @@ def test_consistency_5x5(mode):
             source = source.split() * 2
             reference = reference.split() * 2
 
-            assert_image_equal(
+            if mode == "I":
-                Image.merge(mode, source[: len(mode)]).filter(kernel),
+                source = source[0].convert(mode)
-                Image.merge(mode, reference[: len(mode)]),
+            else:
-            )
+                source = Image.merge(mode, source[: len(mode)])
+            reference = Image.merge(mode, reference[: len(mode)])
+            assert_image_equal(source.filter(kernel), reference)
 
 
 def test_invalid_box_blur_filter():

src/libImaging/Filter.c

@@ -37,6 +37,17 @@ clip8(float in) {
     return (UINT8)in;
 }
 
+static inline INT32
+clip32(float in) {
+    if (in <= 0.0) {
+        return 0;
+    }
+    if (in >= pow(2, 31) - 1) {
+        return pow(2, 31) - 1;
+    }
+    return (INT32)in;
+}
+
 Imaging
 ImagingExpand(Imaging imIn, int xmargin, int ymargin, int mode) {
     Imaging imOut;
@@ -96,8 +107,8 @@ ImagingExpand(Imaging imIn, int xmargin, int ymargin, int mode) {
 void
 ImagingFilter3x3(Imaging imOut, Imaging im, const float *kernel, float offset) {
 #define KERNEL1x3(in0, x, kernel, d)                                             \
-    (_i2f((UINT8)in0[x - d]) * (kernel)[0] + _i2f((UINT8)in0[x]) * (kernel)[1] + \
+    (_i2f(in0[x - d]) * (kernel)[0] + _i2f(in0[x]) * (kernel)[1] + \
-     _i2f((UINT8)in0[x + d]) * (kernel)[2])
+     _i2f(in0[x + d]) * (kernel)[2])
 
     int x = 0, y = 0;
 
@@ -105,6 +116,24 @@ ImagingFilter3x3(Imaging imOut, Imaging im, const float *kernel, float offset) {
     if (im->bands == 1) {
         // Add one time for rounding
         offset += 0.5;
+        if (im->type == IMAGING_TYPE_INT32) {
+            for (y = 1; y < im->ysize - 1; y++) {
+                INT32 *in_1 = (INT32 *)im->image[y - 1];
+                INT32 *in0 = (INT32 *)im->image[y];
+                INT32 *in1 = (INT32 *)im->image[y + 1];
+                INT32 *out = (INT32 *)imOut->image[y];
+
+                out[0] = in0[0];
+                for (x = 1; x < im->xsize - 1; x++) {
+                    float ss = offset;
+                    ss += KERNEL1x3(in1, x, &kernel[0], 1);
+                    ss += KERNEL1x3(in0, x, &kernel[3], 1);
+                    ss += KERNEL1x3(in_1, x, &kernel[6], 1);
+                    out[x] = clip32(ss);
+                }
+                out[x] = in0[x];
+            }
+        } else {
             for (y = 1; y < im->ysize - 1; y++) {
                 UINT8 *in_1 = (UINT8 *)im->image[y - 1];
                 UINT8 *in0 = (UINT8 *)im->image[y];
@@ -121,6 +150,7 @@ ImagingFilter3x3(Imaging imOut, Imaging im, const float *kernel, float offset) {
                 }
                 out[x] = in0[x];
             }
+        }
     } else {
         // Add one time for rounding
         offset += 0.5;
@@ -195,10 +225,10 @@ ImagingFilter3x3(Imaging imOut, Imaging im, const float *kernel, float offset) {
 void
 ImagingFilter5x5(Imaging imOut, Imaging im, const float *kernel, float offset) {
 #define KERNEL1x5(in0, x, kernel, d)                                             \
-    (_i2f((UINT8)in0[x - d - d]) * (kernel)[0] +                                 \
+    (_i2f(in0[x - d - d]) * (kernel)[0] +                                 \
-     _i2f((UINT8)in0[x - d]) * (kernel)[1] + _i2f((UINT8)in0[x]) * (kernel)[2] + \
+     _i2f(in0[x - d]) * (kernel)[1] + _i2f(in0[x]) * (kernel)[2] + \
-     _i2f((UINT8)in0[x + d]) * (kernel)[3] +                                     \
+     _i2f(in0[x + d]) * (kernel)[3] +                                     \
-     _i2f((UINT8)in0[x + d + d]) * (kernel)[4])
+     _i2f(in0[x + d + d]) * (kernel)[4])
 
     int x = 0, y = 0;
 
@@ -207,6 +237,30 @@ ImagingFilter5x5(Imaging imOut, Imaging im, const float *kernel, float offset) {
     if (im->bands == 1) {
         // Add one time for rounding
         offset += 0.5;
+        if (im->type == IMAGING_TYPE_INT32) {
+            for (y = 2; y < im->ysize - 2; y++) {
+                INT32 *in_2 = (INT32 *)im->image[y - 2];
+                INT32 *in_1 = (INT32 *)im->image[y - 1];
+                INT32 *in0 = (INT32 *)im->image[y];
+                INT32 *in1 = (INT32 *)im->image[y + 1];
+                INT32 *in2 = (INT32 *)im->image[y + 2];
+                INT32 *out = (INT32 *)imOut->image[y];
+
+                out[0] = in0[0];
+                out[1] = in0[1];
+                for (x = 2; x < im->xsize - 2; x++) {
+                    float ss = offset;
+                    ss += KERNEL1x5(in2, x, &kernel[0], 1);
+                    ss += KERNEL1x5(in1, x, &kernel[5], 1);
+                    ss += KERNEL1x5(in0, x, &kernel[10], 1);
+                    ss += KERNEL1x5(in_1, x, &kernel[15], 1);
+                    ss += KERNEL1x5(in_2, x, &kernel[20], 1);
+                    out[x] = clip32(ss);
+                }
+                out[x + 0] = in0[x + 0];
+                out[x + 1] = in0[x + 1];
+            }
+        } else {
             for (y = 2; y < im->ysize - 2; y++) {
                 UINT8 *in_2 = (UINT8 *)im->image[y - 2];
                 UINT8 *in_1 = (UINT8 *)im->image[y - 1];
@@ -229,6 +283,7 @@ ImagingFilter5x5(Imaging imOut, Imaging im, const float *kernel, float offset) {
                 out[x + 0] = in0[x + 0];
                 out[x + 1] = in0[x + 1];
             }
+        }
     } else {
         // Add one time for rounding
         offset += 0.5;
@@ -327,7 +382,7 @@ ImagingFilter(Imaging im, int xsize, int ysize, const FLOAT32 *kernel, FLOAT32 o
     Imaging imOut;
     ImagingSectionCookie cookie;
 
-    if (!im || im->type != IMAGING_TYPE_UINT8) {
+    if (im->type != IMAGING_TYPE_UINT8 && im->type != IMAGING_TYPE_INT32) {
         return (Imaging)ImagingError_ModeError();
     }