Enum PaddingMode 

#[repr(i32)]
pub enum PaddingMode {
    kEXPLICIT_ROUND_DOWN = 0,
    kEXPLICIT_ROUND_UP = 1,
    kSAME_UPPER = 2,
    kSAME_LOWER = 3,
}

PaddingMode

Enumerates the modes of padding to perform in convolution, deconvolution and pooling layer, padding mode takes precedence if setPaddingMode() and setPrePadding() are also used.

There are two padding styles, EXPLICIT and SAME with each style having two variants. The EXPLICIT style determine if the final sampling location is used or not. The SAME style determine if the asymmetry in the padding is on the pre or post padding.

Shorthand: I = dimensions of input image. B = prePadding, before the image data. A = postPadding, after the image data. P = delta between input and output S = stride F = filter O = output D = dilation M = I + B + A ; The image data plus any padding DK = 1 + D * (F - 1)

Formulas for Convolution:

• EXPLICIT_ROUND_DOWN:

O = floor((M - DK) / S) + 1

• EXPLICIT_ROUND_UP:

O = ceil((M - DK) / S) + 1

• SAME_UPPER:

O = ceil(I / S) P = floor((I - 1) / S) * S + DK - I; B = floor(P / 2) A = P - B

• SAME_LOWER:

O = ceil(I / S) P = floor((I - 1) / S) * S + DK - I; A = floor(P / 2) B = P - A

Formulas for Deconvolution:

• EXPLICIT_ROUND_DOWN:
• EXPLICIT_ROUND_UP:

O = (I - 1) * S + DK - (B + A)

• SAME_UPPER:

O = min(I * S, (I - 1) * S + DK) P = max(DK - S, 0) B = floor(P / 2) A = P - B

• SAME_LOWER:

O = min(I * S, (I - 1) * S + DK) P = max(DK - S, 0) A = floor(P / 2) B = P - A

Formulas for Pooling:

• EXPLICIT_ROUND_DOWN:

O = floor((M - F) / S) + 1

• EXPLICIT_ROUND_UP:

O = ceil((M - F) / S) + 1

• SAME_UPPER:

O = ceil(I / S) P = floor((I - 1) / S) * S + F - I; B = floor(P / 2) A = P - B

• SAME_LOWER:

O = ceil(I / S) P = floor((I - 1) / S) * S + F - I; A = floor(P / 2) B = P - A

Pooling Example 1:

Given I = {6, 6}, B = {3, 3}, A = {2, 2}, S = {2, 2}, F = {3, 3}. What is O? (B, A can be calculated for SAME_UPPER and SAME_LOWER mode)

• EXPLICIT_ROUND_DOWN:

Computation: M = {6, 6} + {3, 3} + {2, 2} ==> {11, 11} O ==> floor((M - F) / S) + 1 ==> floor(({11, 11} - {3, 3}) / {2, 2}) + {1, 1} ==> floor({8, 8} / {2, 2}) + {1, 1} ==> {5, 5}

• EXPLICIT_ROUND_UP:

Computation: M = {6, 6} + {3, 3} + {2, 2} ==> {11, 11} O ==> ceil((M - F) / S) + 1 ==> ceil(({11, 11} - {3, 3}) / {2, 2}) + {1, 1} ==> ceil({8, 8} / {2, 2}) + {1, 1} ==> {5, 5}

The sample points are {0, 2, 4, 6, 8} in each dimension.

• SAME_UPPER:

Computation: I = {6, 6} S = {2, 2} O = ceil(I / S) = {3, 3} P = floor((I - 1) / S) * S + F - I ==> floor(({6, 6} - {1, 1}) / {2, 2}) * {2, 2} + {3, 3} - {6, 6} ==> {4, 4} + {3, 3} - {6, 6} ==> {1, 1} B = floor({1, 1} / {2, 2}) ==> {0, 0} A = {1, 1} - {0, 0} ==> {1, 1}

• SAME_LOWER:

Computation: I = {6, 6} S = {2, 2} O = ceil(I / S) = {3, 3} P = floor((I - 1) / S) * S + F - I ==> {1, 1} A = floor({1, 1} / {2, 2}) ==> {0, 0} B = {1, 1} - {0, 0} ==> {1, 1}

The sample pointers are {0, 2, 4} in each dimension. SAMPLE_UPPER has {O0, O1, O2, pad} in output in each dimension. SAMPLE_LOWER has {pad, O0, O1, O2} in output in each dimension.

Pooling Example 2:

Given I = {6, 6}, B = {3, 3}, A = {3, 3}, S = {2, 2}, F = {3, 3}. What is O?

Variants

kEXPLICIT_ROUND_DOWN = 0

< Use explicit padding, rounding output size down.

kEXPLICIT_ROUND_UP = 1

< Use explicit padding, rounding output size up.

kSAME_UPPER = 2

< Use SAME padding, with prePadding <= postPadding.

kSAME_LOWER = 3

< Use SAME padding, with prePadding >= postPadding.

Trait Implementations

impl Clone for PaddingMode

fn clone(&self) -> PaddingMode

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl ExternType for PaddingMode

type Id = (n, v, i, n, f, e, r, _1, (), P, a, d, d, i, n, g, M, o, d, e)

A type-level representation of the type’s C++ namespace and type name.

type Kind = Trivial

Either cxx::kind::Opaque or cxx::kind::Trivial.

impl Hash for PaddingMode

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for PaddingMode

fn eq(&self, other: &PaddingMode) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for PaddingMode

impl SharedPtrTarget for PaddingMode

impl StructuralPartialEq for PaddingMode

impl UniquePtrTarget for PaddingMode

impl VectorElement for PaddingMode

impl WeakPtrTarget for PaddingMode