import * as tf from '../../dist/tfjs.esm';
|
|
/**
|
* Pads the smaller dimension of an image tensor with zeros, such that width === height.
|
*
|
* @param imgTensor The image tensor.
|
* @param isCenterImage (optional, default: false) If true, add an equal amount of padding on
|
* both sides of the minor dimension oof the image.
|
* @returns The padded tensor with width === height.
|
*/
|
export function padToSquare(imgTensor: tf.Tensor4D, isCenterImage = false): tf.Tensor4D {
|
return tf.tidy(() => {
|
const [height, width] = imgTensor.shape.slice(1);
|
if (height === width) return imgTensor;
|
const dimDiff = Math.abs(height - width);
|
const paddingAmount = Math.round(dimDiff * (isCenterImage ? 0.5 : 1));
|
const paddingAxis = height > width ? 2 : 1;
|
const createPaddingTensor = (paddingAmountLocal: number): tf.Tensor => {
|
const paddingTensorShape = imgTensor.shape.slice();
|
paddingTensorShape[paddingAxis] = paddingAmountLocal;
|
return tf.fill(paddingTensorShape, 0, 'float32');
|
};
|
const paddingTensorAppend = createPaddingTensor(paddingAmount);
|
const remainingPaddingAmount = dimDiff - (paddingTensorAppend.shape[paddingAxis] as number);
|
const paddingTensorPrepend = isCenterImage && remainingPaddingAmount ? createPaddingTensor(remainingPaddingAmount) : null;
|
const tensorsToStack = [paddingTensorPrepend, imgTensor, paddingTensorAppend]
|
.filter((t) => !!t)
|
.map((t) => tf.cast(t as tf.Tensor4D, 'float32')) as tf.Tensor4D[];
|
return tf.concat(tensorsToStack, paddingAxis);
|
});
|
}
|