crop and flip preprocessor

src/features/preprocessors/crop/shared/meta.ts

@@ -0,0 +1,25 @@
+/**
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+export interface Options {
+  left: number;
+  right: number;
+  top: number;
+  bottom: number;
+}
+
+export const defaultOptions: Options = {
+  left: 0,
+  right: 0,
+  top: 0,
+  bottom: 0,
+};

src/features/preprocessors/crop/shared/missing-types.d.ts

@@ -0,0 +1,13 @@
+/**
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/// <reference path="../../../../../missing-types.d.ts" />

src/features/preprocessors/crop/worker/crop.ts

@@ -0,0 +1,63 @@
+/**
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { Options } from '../shared/meta';
+
+export default async function crop(
+  data: ImageData,
+  opts: Options,
+): Promise<ImageData> {
+  const { left, top, right, bottom } = opts;
+  const source = data.data;
+  const { width, height } = data;
+  const cols = width * 4;
+
+  const newWidth = width - left - right;
+  const newHeight = height - top - bottom;
+  const len = newWidth * newHeight * 4;
+  const pixels = new Uint8ClampedArray(len);
+
+  for (let y = 0; y < newHeight; y++) {
+    for (let x = 0; x < newWidth; x++) {
+      let i = y * cols + x * 4;
+      let j = (top + y) * cols + (left + x) * 4;
+      pixels[i] = source[j];
+      pixels[i + 1] = source[j + 1];
+      pixels[i + 2] = source[j + 2];
+      pixels[i + 3] = source[j + 3];
+    }
+  }
+
+  // let sourceX = left;
+  // let sourceY = top;
+  // let x = 0;
+  // let y = 0;
+  // let i = 0;
+  // while (i < len) {
+  //   let from = sourceY * cols + sourceX * 4;
+
+  //   pixels[i++] = source[from++];
+  //   pixels[i++] = source[from++];
+  //   pixels[i++] = source[from++];
+  //   pixels[i++] = source[from];
+
+  //   if (++x === newWidth) {
+  //     x = 0;
+  //     y++;
+
+  //     sourceX = left;
+  //     sourceY++;
+  //   }
+  // }
+
+  return new ImageData(pixels, newWidth, newHeight);
+}

src/features/preprocessors/crop/worker/missing-types.d.ts

@@ -0,0 +1,13 @@
+/**
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/// <reference path="../../../../../missing-types.d.ts" />

src/features/preprocessors/flip/shared/meta.ts

@@ -0,0 +1,21 @@
+/**
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+export interface Options {
+  horizontal: boolean;
+  vertical: boolean;
+}
+
+export const defaultOptions: Options = {
+  horizontal: false,
+  vertical: false,
+};

src/features/preprocessors/flip/shared/missing-types.d.ts

@@ -0,0 +1,13 @@
+/**
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/// <reference path="../../../../../missing-types.d.ts" />

src/features/preprocessors/flip/worker/flip.ts

@@ -0,0 +1,68 @@
+/**
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { Options } from '../shared/meta';
+
+export default async function flip(
+  data: ImageData,
+  opts: Options,
+): Promise<ImageData> {
+  const { vertical, horizontal } = opts;
+  const source = data.data;
+  const len = source.length;
+  const pixels = new Uint8ClampedArray(len);
+  const { width, height } = data;
+
+  let i = 0;
+  let x = 0;
+  let y = 0;
+  const cols = width * 4;
+  while (i < len) {
+    let from = vertical ? (height - y) * cols + x * 4 : i;
+    if (horizontal) from = from - x * 4 + cols - x * 4; // todo: reduce
+
+    pixels[i++] = source[from++];
+    pixels[i++] = source[from++];
+    pixels[i++] = source[from++];
+    pixels[i++] = source[from];
+
+    if (++x === width) {
+      x = 0;
+      y++;
+    }
+  }
+
+  /*
+  function swap(a: number, b: number) {
+    let tmp = pixels[a];
+    pixels[a] = pixels[b];
+    pixels[b] = tmp;
+  }
+  function swapRgba(a: number, b: number) {
+    swap(a, b);
+    swap(a+1, b+1);
+    swap(a+2, b+2);
+    swap(a+3, b+3);
+  }
+  const COLS = data.width * 4;
+  // for (let y = 0, y2 = (data.height - 1); y < y2; y+=4, y2-=4) {
+  for (let y = 0; y < data.height; y++) {
+    for (let x = 0, x2 = COLS - 4; x < x2; x+=4, x2-=4) {
+      const offsetX = y * COLS;
+      const offsetY = (opts.vertical ? (data.height - y) : y) * COLS;
+      const flippedX = opts.horizontal ? x2 : x;
+      swapRgba(offsetX + x, offsetY + x2);
+    }
+  }
+  */
+  return new ImageData(pixels, data.width, data.height);
+}

src/features/preprocessors/flip/worker/missing-types.d.ts

@@ -0,0 +1,13 @@
+/**
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/// <reference path="../../../../../missing-types.d.ts" />