Merge pull request #7927 from python-pillow/imagemath

Deprecate eval(), replacing it with lambda_eval() and unsafe_eval()

Tests/helper.py

@@ -115,7 +115,9 @@ def assert_image_similar(
 
     diff = 0
     for ach, bch in zip(a.split(), b.split()):
-        chdiff = ImageMath.eval("abs(a - b)", a=ach, b=bch).convert("L")
+        chdiff = ImageMath.lambda_eval(
+            lambda args: abs(args["a"] - args["b"]), a=ach, b=bch
+        ).convert("L")
         diff += sum(i * num for i, num in enumerate(chdiff.histogram()))
 
     ave_diff = diff / (a.size[0] * a.size[1])

Tests/test_image_reduce.py

@@ -186,7 +186,9 @@ def assert_compare_images(
 
     bands = ImageMode.getmode(a.mode).bands
     for band, ach, bch in zip(bands, a.split(), b.split()):
-        ch_diff = ImageMath.eval("convert(abs(a - b), 'L')", a=ach, b=bch)
+        ch_diff = ImageMath.lambda_eval(
+            lambda args: args["convert"](abs(args["a"] - args["b"]), "L"), a=ach, b=bch
+        )
         ch_hist = ch_diff.histogram()
 
         average_diff = sum(i * num for i, num in enumerate(ch_hist)) / (

Tests/test_imagemath.py

@@ -1,214 +0,0 @@
-from __future__ import annotations
-
-import pytest
-
-from PIL import Image, ImageMath
-
-
-def pixel(im: Image.Image | int) -> str | int:
-    if isinstance(im, int):
-        return int(im)  # hack to deal with booleans
-
-    return f"{im.mode} {repr(im.getpixel((0, 0)))}"
-
-
-A = Image.new("L", (1, 1), 1)
-B = Image.new("L", (1, 1), 2)
-Z = Image.new("L", (1, 1), 0)  # Z for zero
-F = Image.new("F", (1, 1), 3)
-I = Image.new("I", (1, 1), 4)  # noqa: E741
-
-A2 = A.resize((2, 2))
-B2 = B.resize((2, 2))
-
-images = {"A": A, "B": B, "F": F, "I": I}
-
-
-def test_sanity() -> None:
-    assert ImageMath.eval("1") == 1
-    assert ImageMath.eval("1+A", A=2) == 3
-    assert pixel(ImageMath.eval("A+B", A=A, B=B)) == "I 3"
-    assert pixel(ImageMath.eval("A+B", images)) == "I 3"
-    assert pixel(ImageMath.eval("float(A)+B", images)) == "F 3.0"
-    assert pixel(ImageMath.eval("int(float(A)+B)", images)) == "I 3"
-
-
-def test_ops() -> None:
-    assert pixel(ImageMath.eval("-A", images)) == "I -1"
-    assert pixel(ImageMath.eval("+B", images)) == "L 2"
-
-    assert pixel(ImageMath.eval("A+B", images)) == "I 3"
-    assert pixel(ImageMath.eval("A-B", images)) == "I -1"
-    assert pixel(ImageMath.eval("A*B", images)) == "I 2"
-    assert pixel(ImageMath.eval("A/B", images)) == "I 0"
-    assert pixel(ImageMath.eval("B**2", images)) == "I 4"
-    assert pixel(ImageMath.eval("B**33", images)) == "I 2147483647"
-
-    assert pixel(ImageMath.eval("float(A)+B", images)) == "F 3.0"
-    assert pixel(ImageMath.eval("float(A)-B", images)) == "F -1.0"
-    assert pixel(ImageMath.eval("float(A)*B", images)) == "F 2.0"
-    assert pixel(ImageMath.eval("float(A)/B", images)) == "F 0.5"
-    assert pixel(ImageMath.eval("float(B)**2", images)) == "F 4.0"
-    assert pixel(ImageMath.eval("float(B)**33", images)) == "F 8589934592.0"
-
-
-@pytest.mark.parametrize(
-    "expression",
-    (
-        "exec('pass')",
-        "(lambda: exec('pass'))()",
-        "(lambda: (lambda: exec('pass'))())()",
-    ),
-)
-def test_prevent_exec(expression: str) -> None:
-    with pytest.raises(ValueError):
-        ImageMath.eval(expression)
-
-
-def test_prevent_double_underscores() -> None:
-    with pytest.raises(ValueError):
-        ImageMath.eval("1", {"__": None})
-
-
-def test_prevent_builtins() -> None:
-    with pytest.raises(ValueError):
-        ImageMath.eval("(lambda: exec('exit()'))()", {"exec": None})
-
-
-def test_logical() -> None:
-    assert pixel(ImageMath.eval("not A", images)) == 0
-    assert pixel(ImageMath.eval("A and B", images)) == "L 2"
-    assert pixel(ImageMath.eval("A or B", images)) == "L 1"
-
-
-def test_convert() -> None:
-    assert pixel(ImageMath.eval("convert(A+B, 'L')", images)) == "L 3"
-    assert pixel(ImageMath.eval("convert(A+B, '1')", images)) == "1 0"
-    assert pixel(ImageMath.eval("convert(A+B, 'RGB')", images)) == "RGB (3, 3, 3)"
-
-
-def test_compare() -> None:
-    assert pixel(ImageMath.eval("min(A, B)", images)) == "I 1"
-    assert pixel(ImageMath.eval("max(A, B)", images)) == "I 2"
-    assert pixel(ImageMath.eval("A == 1", images)) == "I 1"
-    assert pixel(ImageMath.eval("A == 2", images)) == "I 0"
-
-
-def test_one_image_larger() -> None:
-    assert pixel(ImageMath.eval("A+B", A=A2, B=B)) == "I 3"
-    assert pixel(ImageMath.eval("A+B", A=A, B=B2)) == "I 3"
-
-
-def test_abs() -> None:
-    assert pixel(ImageMath.eval("abs(A)", A=A)) == "I 1"
-    assert pixel(ImageMath.eval("abs(B)", B=B)) == "I 2"
-
-
-def test_binary_mod() -> None:
-    assert pixel(ImageMath.eval("A%A", A=A)) == "I 0"
-    assert pixel(ImageMath.eval("B%B", B=B)) == "I 0"
-    assert pixel(ImageMath.eval("A%B", A=A, B=B)) == "I 1"
-    assert pixel(ImageMath.eval("B%A", A=A, B=B)) == "I 0"
-    assert pixel(ImageMath.eval("Z%A", A=A, Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("Z%B", B=B, Z=Z)) == "I 0"
-
-
-def test_bitwise_invert() -> None:
-    assert pixel(ImageMath.eval("~Z", Z=Z)) == "I -1"
-    assert pixel(ImageMath.eval("~A", A=A)) == "I -2"
-    assert pixel(ImageMath.eval("~B", B=B)) == "I -3"
-
-
-def test_bitwise_and() -> None:
-    assert pixel(ImageMath.eval("Z&Z", A=A, Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("Z&A", A=A, Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("A&Z", A=A, Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("A&A", A=A, Z=Z)) == "I 1"
-
-
-def test_bitwise_or() -> None:
-    assert pixel(ImageMath.eval("Z|Z", A=A, Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("Z|A", A=A, Z=Z)) == "I 1"
-    assert pixel(ImageMath.eval("A|Z", A=A, Z=Z)) == "I 1"
-    assert pixel(ImageMath.eval("A|A", A=A, Z=Z)) == "I 1"
-
-
-def test_bitwise_xor() -> None:
-    assert pixel(ImageMath.eval("Z^Z", A=A, Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("Z^A", A=A, Z=Z)) == "I 1"
-    assert pixel(ImageMath.eval("A^Z", A=A, Z=Z)) == "I 1"
-    assert pixel(ImageMath.eval("A^A", A=A, Z=Z)) == "I 0"
-
-
-def test_bitwise_leftshift() -> None:
-    assert pixel(ImageMath.eval("Z<<0", Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("Z<<1", Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("A<<0", A=A)) == "I 1"
-    assert pixel(ImageMath.eval("A<<1", A=A)) == "I 2"
-
-
-def test_bitwise_rightshift() -> None:
-    assert pixel(ImageMath.eval("Z>>0", Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("Z>>1", Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("A>>0", A=A)) == "I 1"
-    assert pixel(ImageMath.eval("A>>1", A=A)) == "I 0"
-
-
-def test_logical_eq() -> None:
-    assert pixel(ImageMath.eval("A==A", A=A)) == "I 1"
-    assert pixel(ImageMath.eval("B==B", B=B)) == "I 1"
-    assert pixel(ImageMath.eval("A==B", A=A, B=B)) == "I 0"
-    assert pixel(ImageMath.eval("B==A", A=A, B=B)) == "I 0"
-
-
-def test_logical_ne() -> None:
-    assert pixel(ImageMath.eval("A!=A", A=A)) == "I 0"
-    assert pixel(ImageMath.eval("B!=B", B=B)) == "I 0"
-    assert pixel(ImageMath.eval("A!=B", A=A, B=B)) == "I 1"
-    assert pixel(ImageMath.eval("B!=A", A=A, B=B)) == "I 1"
-
-
-def test_logical_lt() -> None:
-    assert pixel(ImageMath.eval("A<A", A=A)) == "I 0"
-    assert pixel(ImageMath.eval("B<B", B=B)) == "I 0"
-    assert pixel(ImageMath.eval("A<B", A=A, B=B)) == "I 1"
-    assert pixel(ImageMath.eval("B<A", A=A, B=B)) == "I 0"
-
-
-def test_logical_le() -> None:
-    assert pixel(ImageMath.eval("A<=A", A=A)) == "I 1"
-    assert pixel(ImageMath.eval("B<=B", B=B)) == "I 1"
-    assert pixel(ImageMath.eval("A<=B", A=A, B=B)) == "I 1"
-    assert pixel(ImageMath.eval("B<=A", A=A, B=B)) == "I 0"
-
-
-def test_logical_gt() -> None:
-    assert pixel(ImageMath.eval("A>A", A=A)) == "I 0"
-    assert pixel(ImageMath.eval("B>B", B=B)) == "I 0"
-    assert pixel(ImageMath.eval("A>B", A=A, B=B)) == "I 0"
-    assert pixel(ImageMath.eval("B>A", A=A, B=B)) == "I 1"
-
-
-def test_logical_ge() -> None:
-    assert pixel(ImageMath.eval("A>=A", A=A)) == "I 1"
-    assert pixel(ImageMath.eval("B>=B", B=B)) == "I 1"
-    assert pixel(ImageMath.eval("A>=B", A=A, B=B)) == "I 0"
-    assert pixel(ImageMath.eval("B>=A", A=A, B=B)) == "I 1"
-
-
-def test_logical_equal() -> None:
-    assert pixel(ImageMath.eval("equal(A, A)", A=A)) == "I 1"
-    assert pixel(ImageMath.eval("equal(B, B)", B=B)) == "I 1"
-    assert pixel(ImageMath.eval("equal(Z, Z)", Z=Z)) == "I 1"
-    assert pixel(ImageMath.eval("equal(A, B)", A=A, B=B)) == "I 0"
-    assert pixel(ImageMath.eval("equal(B, A)", A=A, B=B)) == "I 0"
-    assert pixel(ImageMath.eval("equal(A, Z)", A=A, Z=Z)) == "I 0"
-
-
-def test_logical_not_equal() -> None:
-    assert pixel(ImageMath.eval("notequal(A, A)", A=A)) == "I 0"
-    assert pixel(ImageMath.eval("notequal(B, B)", B=B)) == "I 0"
-    assert pixel(ImageMath.eval("notequal(Z, Z)", Z=Z)) == "I 0"
-    assert pixel(ImageMath.eval("notequal(A, B)", A=A, B=B)) == "I 1"
-    assert pixel(ImageMath.eval("notequal(B, A)", A=A, B=B)) == "I 1"
-    assert pixel(ImageMath.eval("notequal(A, Z)", A=A, Z=Z)) == "I 1"

Tests/test_imagemath_lambda_eval.py

@@ -0,0 +1,496 @@
+from __future__ import annotations
+
+from PIL import Image, ImageMath
+
+
+def pixel(im: Image.Image | int) -> str | int:
+    if isinstance(im, int):
+        return int(im)  # hack to deal with booleans
+
+    return f"{im.mode} {repr(im.getpixel((0, 0)))}"
+
+
+A = Image.new("L", (1, 1), 1)
+B = Image.new("L", (1, 1), 2)
+Z = Image.new("L", (1, 1), 0)  # Z for zero
+F = Image.new("F", (1, 1), 3)
+I = Image.new("I", (1, 1), 4)  # noqa: E741
+
+A2 = A.resize((2, 2))
+B2 = B.resize((2, 2))
+
+images = {"A": A, "B": B, "F": F, "I": I}
+
+
+def test_sanity() -> None:
+    assert ImageMath.lambda_eval(lambda args: 1) == 1
+    assert ImageMath.lambda_eval(lambda args: 1 + args["A"], A=2) == 3
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] + args["B"], A=A, B=B))
+        == "I 3"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] + args["B"], images))
+        == "I 3"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["float"](args["A"]) + args["B"], images
+            )
+        )
+        == "F 3.0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["int"](args["float"](args["A"]) + args["B"]), images
+            )
+        )
+        == "I 3"
+    )
+
+
+def test_ops() -> None:
+    assert pixel(ImageMath.lambda_eval(lambda args: args["A"] * -1, images)) == "I -1"
+
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] + args["B"], images))
+        == "I 3"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] - args["B"], images))
+        == "I -1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] * args["B"], images))
+        == "I 2"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] / args["B"], images))
+        == "I 0"
+    )
+    assert pixel(ImageMath.lambda_eval(lambda args: args["B"] ** 2, images)) == "I 4"
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] ** 33, images))
+        == "I 2147483647"
+    )
+
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["float"](args["A"]) + args["B"], images
+            )
+        )
+        == "F 3.0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["float"](args["A"]) - args["B"], images
+            )
+        )
+        == "F -1.0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["float"](args["A"]) * args["B"], images
+            )
+        )
+        == "F 2.0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["float"](args["A"]) / args["B"], images
+            )
+        )
+        == "F 0.5"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["float"](args["B"]) ** 2, images))
+        == "F 4.0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(lambda args: args["float"](args["B"]) ** 33, images)
+        )
+        == "F 8589934592.0"
+    )
+
+
+def test_logical() -> None:
+    assert pixel(ImageMath.lambda_eval(lambda args: not args["A"], images)) == 0
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] and args["B"], images))
+        == "L 2"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] or args["B"], images))
+        == "L 1"
+    )
+
+
+def test_convert() -> None:
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["convert"](args["A"] + args["B"], "L"), images
+            )
+        )
+        == "L 3"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["convert"](args["A"] + args["B"], "1"), images
+            )
+        )
+        == "1 0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["convert"](args["A"] + args["B"], "RGB"), images
+            )
+        )
+        == "RGB (3, 3, 3)"
+    )
+
+
+def test_compare() -> None:
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["min"](args["A"], args["B"]), images
+            )
+        )
+        == "I 1"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["max"](args["A"], args["B"]), images
+            )
+        )
+        == "I 2"
+    )
+    assert pixel(ImageMath.lambda_eval(lambda args: args["A"] == 1, images)) == "I 1"
+    assert pixel(ImageMath.lambda_eval(lambda args: args["A"] == 2, images)) == "I 0"
+
+
+def test_one_image_larger() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] + args["B"], A=A2, B=B))
+        == "I 3"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] + args["B"], A=A, B=B2))
+        == "I 3"
+    )
+
+
+def test_abs() -> None:
+    assert pixel(ImageMath.lambda_eval(lambda args: abs(args["A"]), A=A)) == "I 1"
+    assert pixel(ImageMath.lambda_eval(lambda args: abs(args["B"]), B=B)) == "I 2"
+
+
+def test_binary_mod() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] % args["A"], A=A)) == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] % args["B"], B=B)) == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] % args["B"], A=A, B=B))
+        == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] % args["A"], A=A, B=B))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["Z"] % args["A"], A=A, Z=Z))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["Z"] % args["B"], B=B, Z=Z))
+        == "I 0"
+    )
+
+
+def test_bitwise_invert() -> None:
+    assert pixel(ImageMath.lambda_eval(lambda args: ~args["Z"], Z=Z)) == "I -1"
+    assert pixel(ImageMath.lambda_eval(lambda args: ~args["A"], A=A)) == "I -2"
+    assert pixel(ImageMath.lambda_eval(lambda args: ~args["B"], B=B)) == "I -3"
+
+
+def test_bitwise_and() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["Z"] & args["Z"], A=A, Z=Z))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["Z"] & args["A"], A=A, Z=Z))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] & args["Z"], A=A, Z=Z))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] & args["A"], A=A, Z=Z))
+        == "I 1"
+    )
+
+
+def test_bitwise_or() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["Z"] | args["Z"], A=A, Z=Z))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["Z"] | args["A"], A=A, Z=Z))
+        == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] | args["Z"], A=A, Z=Z))
+        == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] | args["A"], A=A, Z=Z))
+        == "I 1"
+    )
+
+
+def test_bitwise_xor() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["Z"] ^ args["Z"], A=A, Z=Z))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["Z"] ^ args["A"], A=A, Z=Z))
+        == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] ^ args["Z"], A=A, Z=Z))
+        == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] ^ args["A"], A=A, Z=Z))
+        == "I 0"
+    )
+
+
+def test_bitwise_leftshift() -> None:
+    assert pixel(ImageMath.lambda_eval(lambda args: args["Z"] << 0, Z=Z)) == "I 0"
+    assert pixel(ImageMath.lambda_eval(lambda args: args["Z"] << 1, Z=Z)) == "I 0"
+    assert pixel(ImageMath.lambda_eval(lambda args: args["A"] << 0, A=A)) == "I 1"
+    assert pixel(ImageMath.lambda_eval(lambda args: args["A"] << 1, A=A)) == "I 2"
+
+
+def test_bitwise_rightshift() -> None:
+    assert pixel(ImageMath.lambda_eval(lambda args: args["Z"] >> 0, Z=Z)) == "I 0"
+    assert pixel(ImageMath.lambda_eval(lambda args: args["Z"] >> 1, Z=Z)) == "I 0"
+    assert pixel(ImageMath.lambda_eval(lambda args: args["A"] >> 0, A=A)) == "I 1"
+    assert pixel(ImageMath.lambda_eval(lambda args: args["A"] >> 1, A=A)) == "I 0"
+
+
+def test_logical_eq() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] == args["A"], A=A)) == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] == args["B"], B=B)) == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] == args["B"], A=A, B=B))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] == args["A"], A=A, B=B))
+        == "I 0"
+    )
+
+
+def test_logical_ne() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] != args["A"], A=A)) == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] != args["B"], B=B)) == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] != args["B"], A=A, B=B))
+        == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] != args["A"], A=A, B=B))
+        == "I 1"
+    )
+
+
+def test_logical_lt() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] < args["A"], A=A)) == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] < args["B"], B=B)) == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] < args["B"], A=A, B=B))
+        == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] < args["A"], A=A, B=B))
+        == "I 0"
+    )
+
+
+def test_logical_le() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] <= args["A"], A=A)) == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] <= args["B"], B=B)) == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] <= args["B"], A=A, B=B))
+        == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] <= args["A"], A=A, B=B))
+        == "I 0"
+    )
+
+
+def test_logical_gt() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] > args["A"], A=A)) == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] > args["B"], B=B)) == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] > args["B"], A=A, B=B))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] > args["A"], A=A, B=B))
+        == "I 1"
+    )
+
+
+def test_logical_ge() -> None:
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] >= args["A"], A=A)) == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] >= args["B"], B=B)) == "I 1"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["A"] >= args["B"], A=A, B=B))
+        == "I 0"
+    )
+    assert (
+        pixel(ImageMath.lambda_eval(lambda args: args["B"] >= args["A"], A=A, B=B))
+        == "I 1"
+    )
+
+
+def test_logical_equal() -> None:
+    assert (
+        pixel(
+            ImageMath.lambda_eval(lambda args: args["equal"](args["A"], args["A"]), A=A)
+        )
+        == "I 1"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(lambda args: args["equal"](args["B"], args["B"]), B=B)
+        )
+        == "I 1"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(lambda args: args["equal"](args["Z"], args["Z"]), Z=Z)
+        )
+        == "I 1"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["equal"](args["A"], args["B"]), A=A, B=B
+            )
+        )
+        == "I 0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["equal"](args["B"], args["A"]), A=A, B=B
+            )
+        )
+        == "I 0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["equal"](args["A"], args["Z"]), A=A, Z=Z
+            )
+        )
+        == "I 0"
+    )
+
+
+def test_logical_not_equal() -> None:
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["notequal"](args["A"], args["A"]), A=A
+            )
+        )
+        == "I 0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["notequal"](args["B"], args["B"]), B=B
+            )
+        )
+        == "I 0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["notequal"](args["Z"], args["Z"]), Z=Z
+            )
+        )
+        == "I 0"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["notequal"](args["A"], args["B"]), A=A, B=B
+            )
+        )
+        == "I 1"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["notequal"](args["B"], args["A"]), A=A, B=B
+            )
+        )
+        == "I 1"
+    )
+    assert (
+        pixel(
+            ImageMath.lambda_eval(
+                lambda args: args["notequal"](args["A"], args["Z"]), A=A, Z=Z
+            )
+        )
+        == "I 1"
+    )

Tests/test_imagemath_unsafe_eval.py

@@ -0,0 +1,221 @@
+from __future__ import annotations
+
+import pytest
+
+from PIL import Image, ImageMath
+
+
+def pixel(im: Image.Image | int) -> str | int:
+    if isinstance(im, int):
+        return int(im)  # hack to deal with booleans
+
+    return f"{im.mode} {repr(im.getpixel((0, 0)))}"
+
+
+A = Image.new("L", (1, 1), 1)
+B = Image.new("L", (1, 1), 2)
+Z = Image.new("L", (1, 1), 0)  # Z for zero
+F = Image.new("F", (1, 1), 3)
+I = Image.new("I", (1, 1), 4)  # noqa: E741
+
+A2 = A.resize((2, 2))
+B2 = B.resize((2, 2))
+
+images = {"A": A, "B": B, "F": F, "I": I}
+
+
+def test_sanity() -> None:
+    assert ImageMath.unsafe_eval("1") == 1
+    assert ImageMath.unsafe_eval("1+A", A=2) == 3
+    assert pixel(ImageMath.unsafe_eval("A+B", A=A, B=B)) == "I 3"
+    assert pixel(ImageMath.unsafe_eval("A+B", images)) == "I 3"
+    assert pixel(ImageMath.unsafe_eval("float(A)+B", images)) == "F 3.0"
+    assert pixel(ImageMath.unsafe_eval("int(float(A)+B)", images)) == "I 3"
+
+
+def test_eval_deprecated() -> None:
+    with pytest.warns(DeprecationWarning):
+        assert ImageMath.eval("1") == 1
+
+
+def test_ops() -> None:
+    assert pixel(ImageMath.unsafe_eval("-A", images)) == "I -1"
+    assert pixel(ImageMath.unsafe_eval("+B", images)) == "L 2"
+
+    assert pixel(ImageMath.unsafe_eval("A+B", images)) == "I 3"
+    assert pixel(ImageMath.unsafe_eval("A-B", images)) == "I -1"
+    assert pixel(ImageMath.unsafe_eval("A*B", images)) == "I 2"
+    assert pixel(ImageMath.unsafe_eval("A/B", images)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("B**2", images)) == "I 4"
+    assert pixel(ImageMath.unsafe_eval("B**33", images)) == "I 2147483647"
+
+    assert pixel(ImageMath.unsafe_eval("float(A)+B", images)) == "F 3.0"
+    assert pixel(ImageMath.unsafe_eval("float(A)-B", images)) == "F -1.0"
+    assert pixel(ImageMath.unsafe_eval("float(A)*B", images)) == "F 2.0"
+    assert pixel(ImageMath.unsafe_eval("float(A)/B", images)) == "F 0.5"
+    assert pixel(ImageMath.unsafe_eval("float(B)**2", images)) == "F 4.0"
+    assert pixel(ImageMath.unsafe_eval("float(B)**33", images)) == "F 8589934592.0"
+
+
+@pytest.mark.parametrize(
+    "expression",
+    (
+        "exec('pass')",
+        "(lambda: exec('pass'))()",
+        "(lambda: (lambda: exec('pass'))())()",
+    ),
+)
+def test_prevent_exec(expression: str) -> None:
+    with pytest.raises(ValueError):
+        ImageMath.unsafe_eval(expression)
+
+
+def test_prevent_double_underscores() -> None:
+    with pytest.raises(ValueError):
+        ImageMath.unsafe_eval("1", {"__": None})
+
+
+def test_prevent_builtins() -> None:
+    with pytest.raises(ValueError):
+        ImageMath.unsafe_eval("(lambda: exec('exit()'))()", {"exec": None})
+
+
+def test_logical() -> None:
+    assert pixel(ImageMath.unsafe_eval("not A", images)) == 0
+    assert pixel(ImageMath.unsafe_eval("A and B", images)) == "L 2"
+    assert pixel(ImageMath.unsafe_eval("A or B", images)) == "L 1"
+
+
+def test_convert() -> None:
+    assert pixel(ImageMath.unsafe_eval("convert(A+B, 'L')", images)) == "L 3"
+    assert pixel(ImageMath.unsafe_eval("convert(A+B, '1')", images)) == "1 0"
+    assert (
+        pixel(ImageMath.unsafe_eval("convert(A+B, 'RGB')", images)) == "RGB (3, 3, 3)"
+    )
+
+
+def test_compare() -> None:
+    assert pixel(ImageMath.unsafe_eval("min(A, B)", images)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("max(A, B)", images)) == "I 2"
+    assert pixel(ImageMath.unsafe_eval("A == 1", images)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A == 2", images)) == "I 0"
+
+
+def test_one_image_larger() -> None:
+    assert pixel(ImageMath.unsafe_eval("A+B", A=A2, B=B)) == "I 3"
+    assert pixel(ImageMath.unsafe_eval("A+B", A=A, B=B2)) == "I 3"
+
+
+def test_abs() -> None:
+    assert pixel(ImageMath.unsafe_eval("abs(A)", A=A)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("abs(B)", B=B)) == "I 2"
+
+
+def test_binary_mod() -> None:
+    assert pixel(ImageMath.unsafe_eval("A%A", A=A)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("B%B", B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("A%B", A=A, B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("B%A", A=A, B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("Z%A", A=A, Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("Z%B", B=B, Z=Z)) == "I 0"
+
+
+def test_bitwise_invert() -> None:
+    assert pixel(ImageMath.unsafe_eval("~Z", Z=Z)) == "I -1"
+    assert pixel(ImageMath.unsafe_eval("~A", A=A)) == "I -2"
+    assert pixel(ImageMath.unsafe_eval("~B", B=B)) == "I -3"
+
+
+def test_bitwise_and() -> None:
+    assert pixel(ImageMath.unsafe_eval("Z&Z", A=A, Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("Z&A", A=A, Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("A&Z", A=A, Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("A&A", A=A, Z=Z)) == "I 1"
+
+
+def test_bitwise_or() -> None:
+    assert pixel(ImageMath.unsafe_eval("Z|Z", A=A, Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("Z|A", A=A, Z=Z)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A|Z", A=A, Z=Z)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A|A", A=A, Z=Z)) == "I 1"
+
+
+def test_bitwise_xor() -> None:
+    assert pixel(ImageMath.unsafe_eval("Z^Z", A=A, Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("Z^A", A=A, Z=Z)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A^Z", A=A, Z=Z)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A^A", A=A, Z=Z)) == "I 0"
+
+
+def test_bitwise_leftshift() -> None:
+    assert pixel(ImageMath.unsafe_eval("Z<<0", Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("Z<<1", Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("A<<0", A=A)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A<<1", A=A)) == "I 2"
+
+
+def test_bitwise_rightshift() -> None:
+    assert pixel(ImageMath.unsafe_eval("Z>>0", Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("Z>>1", Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("A>>0", A=A)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A>>1", A=A)) == "I 0"
+
+
+def test_logical_eq() -> None:
+    assert pixel(ImageMath.unsafe_eval("A==A", A=A)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("B==B", B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A==B", A=A, B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("B==A", A=A, B=B)) == "I 0"
+
+
+def test_logical_ne() -> None:
+    assert pixel(ImageMath.unsafe_eval("A!=A", A=A)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("B!=B", B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("A!=B", A=A, B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("B!=A", A=A, B=B)) == "I 1"
+
+
+def test_logical_lt() -> None:
+    assert pixel(ImageMath.unsafe_eval("A<A", A=A)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("B<B", B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("A<B", A=A, B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("B<A", A=A, B=B)) == "I 0"
+
+
+def test_logical_le() -> None:
+    assert pixel(ImageMath.unsafe_eval("A<=A", A=A)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("B<=B", B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A<=B", A=A, B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("B<=A", A=A, B=B)) == "I 0"
+
+
+def test_logical_gt() -> None:
+    assert pixel(ImageMath.unsafe_eval("A>A", A=A)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("B>B", B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("A>B", A=A, B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("B>A", A=A, B=B)) == "I 1"
+
+
+def test_logical_ge() -> None:
+    assert pixel(ImageMath.unsafe_eval("A>=A", A=A)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("B>=B", B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("A>=B", A=A, B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("B>=A", A=A, B=B)) == "I 1"
+
+
+def test_logical_equal() -> None:
+    assert pixel(ImageMath.unsafe_eval("equal(A, A)", A=A)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("equal(B, B)", B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("equal(Z, Z)", Z=Z)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("equal(A, B)", A=A, B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("equal(B, A)", A=A, B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("equal(A, Z)", A=A, Z=Z)) == "I 0"
+
+
+def test_logical_not_equal() -> None:
+    assert pixel(ImageMath.unsafe_eval("notequal(A, A)", A=A)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("notequal(B, B)", B=B)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("notequal(Z, Z)", Z=Z)) == "I 0"
+    assert pixel(ImageMath.unsafe_eval("notequal(A, B)", A=A, B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("notequal(B, A)", A=A, B=B)) == "I 1"
+    assert pixel(ImageMath.unsafe_eval("notequal(A, Z)", A=A, Z=Z)) == "I 1"

docs/deprecations.rst

@@ -92,6 +92,14 @@ Deprecated                                    Use instead
                                               :py:data:`sys.version_info`, and ``PIL.__version__``
 ============================================  ====================================================
 
+ImageMath eval()
+^^^^^^^^^^^^^^^^
+
+.. deprecated:: 10.3.0
+
+``ImageMath.eval()`` has been deprecated. Use :py:meth:`~PIL.ImageMath.lambda_eval` or
+:py:meth:`~PIL.ImageMath.unsafe_eval` instead.
+
 Removed features
 ----------------
 

docs/reference/ImageMath.rst

@@ -4,9 +4,12 @@
 :py:mod:`~PIL.ImageMath` Module
 ===============================
 
-The :py:mod:`~PIL.ImageMath` module can be used to evaluate “image expressions”. The
+The :py:mod:`~PIL.ImageMath` module can be used to evaluate “image expressions”, that
-module provides a single :py:meth:`~PIL.ImageMath.eval` function, which takes
+can take a number of images and generate a result.
-an expression string and one or more images.
+
+:py:mod:`~PIL.ImageMath` only supports single-layer images. To process multi-band
+images, use the :py:meth:`~PIL.Image.Image.split` method or :py:func:`~PIL.Image.merge`
+function.
 
 Example: Using the :py:mod:`~PIL.ImageMath` module
 --------------------------------------------------
@@ -17,35 +20,69 @@ Example: Using the :py:mod:`~PIL.ImageMath` module
 
     with Image.open("image1.jpg") as im1:
         with Image.open("image2.jpg") as im2:
+            out = ImageMath.lambda_eval(
+              lambda args: args["convert"](args["min"](args["a"], args["b"]), 'L'),
+              a=im1,
+              b=im2
+            )
+            out = ImageMath.unsafe_eval(
+              "convert(min(a, b), 'L')",
+              a=im1,
+              b=im2
+            )
 
-            out = ImageMath.eval("convert(min(a, b), 'L')", a=im1, b=im2)
+.. py:function:: lambda_eval(expression, environment)
-            out.save("result.png")
 
-.. py:function:: eval(expression, environment)
+    Returns the result of an image function.
 
-    Evaluate expression in the given environment.
+    :param expression: A function that receives a dictionary.
+    :param options: Values to add to the function's dictionary, mapping image
+                    names to Image instances. You can use one or more keyword
+                    arguments instead of a dictionary, as shown in the above
+                    example. Note that the names must be valid Python
+                    identifiers.
+    :return: An image, an integer value, a floating point value,
+             or a pixel tuple, depending on the expression.
 
-    In the current version, :py:mod:`~PIL.ImageMath` only supports
+.. py:function:: unsafe_eval(expression, environment)
-    single-layer images. To process multi-band images, use the
+
-    :py:meth:`~PIL.Image.Image.split` method or :py:func:`~PIL.Image.merge`
+    Evaluates an image expression.
-    function.
+
+    .. danger::
+        This uses Python's ``eval()`` function to process the expression string,
+        and carries the security risks of doing so. It is not
+        recommended to process expressions without considering this.
+        :py:meth:`lambda_eval` is a more secure alternative.
+
+    :py:mod:`~PIL.ImageMath` only supports single-layer images. To process multi-band
+    images, use the :py:meth:`~PIL.Image.Image.split` method or
+    :py:func:`~PIL.Image.merge` function.
 
     :param expression: A string which uses the standard Python expression
                        syntax. In addition to the standard operators, you can
                        also use the functions described below.
-    :param environment: A dictionary that maps image names to Image instances.
+    :param options: Values to add to the function's dictionary, mapping image
-                        You can use one or more keyword arguments instead of a
+                    names to Image instances. You can use one or more keyword
-                        dictionary, as shown in the above example. Note that
+                    arguments instead of a dictionary, as shown in the above
-                        the names must be valid Python identifiers.
+                    example. Note that the names must be valid Python
+                    identifiers.
     :return: An image, an integer value, a floating point value,
              or a pixel tuple, depending on the expression.
 
 Expression syntax
 -----------------
 
-Expressions are standard Python expressions, but they’re evaluated in a
+* :py:meth:`lambda_eval` expressions are functions that receive a dictionary
-non-standard environment. You can use PIL methods as usual, plus the following
+  containing images and operators.
-set of operators and functions:
+
+* :py:meth:`unsafe_eval` expressions are standard Python expressions,
+  but they’re evaluated in a non-standard environment.
+
+.. danger::
+  :py:meth:`unsafe_eval` uses Python's ``eval()`` function to process the
+  expression string, and carries the security risks of doing so.
+  It is not recommended to process expressions without considering this.
+  :py:meth:`lambda_eval` is a more secure alternative.
 
 Standard Operators
 ^^^^^^^^^^^^^^^^^^

docs/releasenotes/10.2.0.rst

@@ -29,7 +29,7 @@ they do not extend beyond the bitmap image.
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 If an attacker has control over the keys passed to the
-``environment`` argument of :py:meth:`PIL.ImageMath.eval`, they may be able to execute
+``environment`` argument of :py:meth:`!PIL.ImageMath.eval`, they may be able to execute
 arbitrary code. To prevent this, keys matching the names of builtins and keys
 containing double underscores will now raise a :py:exc:`ValueError`.
 

docs/releasenotes/10.3.0.rst

@@ -4,10 +4,15 @@
 Security
 ========
 
-TODO
+ImageMath eval()
-^^^^
+^^^^^^^^^^^^^^^^
 
-TODO
+.. danger::
+  ``ImageMath.eval()`` uses Python's ``eval()`` function to process the expression
+  string, and carries the security risks of doing so. A direct replacement for this is
+  the new :py:meth:`~PIL.ImageMath.unsafe_eval`, but that carries the same risks. It is
+  not recommended to process expressions without considering this.
+  :py:meth:`~PIL.ImageMath.lambda_eval` is a more secure alternative.
 
 :cve:`YYYY-XXXXX`: TODO
 ^^^^^^^^^^^^^^^^^^^^^^^
@@ -58,6 +63,13 @@ Deprecated                                    Use instead
                                               :py:data:`sys.version_info`, and ``PIL.__version__``
 ============================================  ====================================================
 
+ImageMath.eval()
+^^^^^^^^^^^^^^^^
+
+``ImageMath.eval()`` has been deprecated. Use :py:meth:`~PIL.ImageMath.lambda_eval` or
+:py:meth:`~PIL.ImageMath.unsafe_eval` instead. See earlier security notes for more
+information.
+
 API Changes
 ===========
 

docs/releasenotes/9.0.0.rst

@@ -47,7 +47,7 @@ Google's `OSS-Fuzz`_ project for finding this issue.
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 To limit :py:class:`PIL.ImageMath` to working with images, Pillow
-will now restrict the builtins available to :py:meth:`PIL.ImageMath.eval`. This will
+will now restrict the builtins available to :py:meth:`!PIL.ImageMath.eval`. This will
 help prevent problems arising if users evaluate arbitrary expressions, such as
 ``ImageMath.eval("exec(exit())")``.
 

docs/releasenotes/9.0.1.rst

@@ -18,7 +18,7 @@ has been present since PIL.
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 While Pillow 9.0 restricted top-level builtins available to
-:py:meth:`PIL.ImageMath.eval`, it did not prevent builtins
+:py:meth:`!PIL.ImageMath.eval`, it did not prevent builtins
 available to lambda expressions. These are now also restricted.
 
 Other Changes

src/PIL/GifImagePlugin.py

@@ -652,8 +652,17 @@ def _write_multiple_frames(im, fp, palette):
                         fill = Image.new("P", delta.size, encoderinfo["transparency"])
                         if delta.mode == "RGBA":
                             r, g, b, a = delta.split()
-                            mask = ImageMath.eval(
+                            mask = ImageMath.lambda_eval(
-                                "convert(max(max(max(r, g), b), a) * 255, '1')",
+                                lambda args: args["convert"](
+                                    args["max"](
+                                        args["max"](
+                                            args["max"](args["r"], args["g"]), args["b"]
+                                        ),
+                                        args["a"],
+                                    )
+                                    * 255,
+                                    "1",
+                                ),
                                 r=r,
                                 g=g,
                                 b=b,
@@ -665,7 +674,10 @@ def _write_multiple_frames(im, fp, palette):
                                 delta_l = Image.new("L", delta.size)
                                 delta_l.putdata(delta.getdata())
                                 delta = delta_l
-                            mask = ImageMath.eval("convert(im * 255, '1')", im=delta)
+                            mask = ImageMath.lambda_eval(
+                                lambda args: args["convert"](args["im"] * 255, "1"),
+                                im=delta,
+                            )
                         diff_frame.paste(fill, mask=ImageOps.invert(mask))
             else:
                 bbox = None

src/PIL/ImageMath.py

@@ -18,9 +18,10 @@ from __future__ import annotations
 
 import builtins
 from types import CodeType
-from typing import Any
+from typing import Any, Callable
 
 from . import Image, _imagingmath
+from ._deprecate import deprecate
 
 
 class _Operand:
@@ -235,9 +236,55 @@ ops = {
 }
 
 
-def eval(expression: str, _dict: dict[str, Any] = {}, **kw: Any) -> Any:
+def lambda_eval(
+    expression: Callable[[dict[str, Any]], Any],
+    options: dict[str, Any] = {},
+    **kw: Any,
+) -> Any:
     """
-    Evaluates an image expression.
+    Returns the result of an image function.
+
+    :py:mod:`~PIL.ImageMath` only supports single-layer images. To process multi-band
+    images, use the :py:meth:`~PIL.Image.Image.split` method or
+    :py:func:`~PIL.Image.merge` function.
+
+    :param expression: A function that receives a dictionary.
+    :param options: Values to add to the function's dictionary. You
+                    can either use a dictionary, or one or more keyword
+                    arguments.
+    :return: The expression result. This is usually an image object, but can
+             also be an integer, a floating point value, or a pixel tuple,
+             depending on the expression.
+    """
+
+    args: dict[str, Any] = ops.copy()
+    args.update(options)
+    args.update(kw)
+    for k, v in args.items():
+        if hasattr(v, "im"):
+            args[k] = _Operand(v)
+
+    out = expression(args)
+    try:
+        return out.im
+    except AttributeError:
+        return out
+
+
+def unsafe_eval(
+    expression: str,
+    options: dict[str, Any] = {},
+    **kw: Any,
+) -> Any:
+    """
+    Evaluates an image expression. This uses Python's ``eval()`` function to process
+    the expression string, and carries the security risks of doing so. It is not
+    recommended to process expressions without considering this.
+    :py:meth:`~lambda_eval` is a more secure alternative.
+
+    :py:mod:`~PIL.ImageMath` only supports single-layer images. To process multi-band
+    images, use the :py:meth:`~PIL.Image.Image.split` method or
+    :py:func:`~PIL.Image.merge` function.
 
     :param expression: A string containing a Python-style expression.
     :param options: Values to add to the evaluation context.  You
@@ -250,12 +297,12 @@ def eval(expression: str, _dict: dict[str, Any] = {}, **kw: Any) -> Any:
 
     # build execution namespace
     args: dict[str, Any] = ops.copy()
-    for k in list(_dict.keys()) + list(kw.keys()):
+    for k in list(options.keys()) + list(kw.keys()):
         if "__" in k or hasattr(builtins, k):
             msg = f"'{k}' not allowed"
             raise ValueError(msg)
 
-    args.update(_dict)
+    args.update(options)
     args.update(kw)
     for k, v in args.items():
         if hasattr(v, "im"):
@@ -279,3 +326,32 @@ def eval(expression: str, _dict: dict[str, Any] = {}, **kw: Any) -> Any:
         return out.im
     except AttributeError:
         return out
+
+
+def eval(
+    expression: str,
+    _dict: dict[str, Any] = {},
+    **kw: Any,
+) -> Any:
+    """
+    Evaluates an image expression.
+
+    Deprecated. Use lambda_eval() or unsafe_eval() instead.
+
+    :param expression: A string containing a Python-style expression.
+    :param _dict: Values to add to the evaluation context.  You
+                  can either use a dictionary, or one or more keyword
+                  arguments.
+    :return: The evaluated expression. This is usually an image object, but can
+             also be an integer, a floating point value, or a pixel tuple,
+             depending on the expression.
+
+    ..  deprecated:: 10.3.0
+    """
+
+    deprecate(
+        "ImageMath.eval",
+        12,
+        "ImageMath.lambda_eval or ImageMath.unsafe_eval",
+    )
+    return unsafe_eval(expression, _dict, **kw)