re-organize image utils and lanczos

LICENSE

@@ -486,3 +486,41 @@ INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
 THIS SOFTWARE.
+
+---
+
+Some code has been repurposed from <https://github.com/rgba-image/lanczos>
+
+MIT License
+
+Copyright (c) 2018 Nik Coughlin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Adapted to typescript from pica: <https://github.com/nodeca/pica>
+
+(The MIT License)
+
+Copyright (C) 2014-2017 by Vitaly Puzrin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

src/tools/index.ts

@@ -1,3 +1,4 @@
 export * from './delaunator';
+export * from './lanczos';
 export * from './orthodrome';
 export * from './polylabel';

src/tools/lanczos/index.ts → src/tools/lanczos.ts

@@ -1,6 +1,4 @@
-import { copy, createImage, resize } from './util';
-
-export * from './util';
+import { copyImage, createImage, resizeImage } from '../util';
 
 /**
  * Lanczos filter function for downscaling
@@ -50,13 +48,13 @@ export function lanczos(
     dw === dest.width &&
     dh === dest.height
   ) {
-    resize(source, dest, use2);
+    resizeImage(source, dest, use2);
     return;
   }
 
   const croppedSource = createImage(sw, sh);
   const croppedDest = createImage(dw, dh);
-  copy(source, croppedSource, sx, sy);
-  resize(croppedSource, croppedDest, use2);
-  copy(croppedDest, dest, 0, 0, croppedDest.width, croppedDest.height, dx, dy);
+  copyImage(source, croppedSource, sx, sy);
+  resizeImage(croppedSource, croppedDest, use2);
+  copyImage(croppedDest, dest, 0, 0, croppedDest.width, croppedDest.height, dx, dy);
 }

src/tools/lanczos/util.ts → src/util/image.ts

@@ -34,7 +34,7 @@ function toFixedPoint(value: number): number {
  * @param use2 - use 2nd lanczos filter instead of 3rd
  * @returns - filter
  */
-export function filters(
+function filters(
   srcSize: number,
   destSize: number,
   scale: number,
@@ -121,74 +121,6 @@ export function filters(
   return packedFilter;
 }
 
-/**
- * Convolve an image with a filter
- * @param source - the source image
- * @param dest - the destination image
- * @param sw - source width
- * @param sh - source height
- * @param dw - destination width
- * @param filters - image filter
- */
-export function convolve(
-  source: Uint8ClampedArray,
-  dest: Uint8ClampedArray,
-  sw: number,
-  sh: number,
-  dw: number,
-  filters: Int16Array,
-): void {
-  let srcOffset = 0;
-  let destOffset = 0;
-
-  // For each row
-  for (let sourceY = 0; sourceY < sh; sourceY++) {
-    let filterPtr = 0;
-
-    // Apply precomputed filters to each destination row point
-    for (let destX = 0; destX < dw; destX++) {
-      // Get the filter that determines the current output pixel.
-      const filterShift = filters[filterPtr++];
-
-      let srcPtr = (srcOffset + filterShift * 4) | 0;
-
-      let r = 0;
-      let g = 0;
-      let b = 0;
-      let a = 0;
-
-      // Apply the filter to the row to get the destination pixel r, g, b, a
-      for (let filterSize = filters[filterPtr++]; filterSize > 0; filterSize--) {
-        const filterValue = filters[filterPtr++];
-
-        r = (r + filterValue * source[srcPtr]) | 0;
-        g = (g + filterValue * source[srcPtr + 1]) | 0;
-        b = (b + filterValue * source[srcPtr + 2]) | 0;
-        a = (a + filterValue * source[srcPtr + 3]) | 0;
-
-        srcPtr = (srcPtr + 4) | 0;
-      }
-
-      // Bring this value back in range. All of the filter scaling factors
-      // are in fixed point with FIXED_FRAC_BITS bits of fractional part.
-      //
-      // (!) Add 1/2 of value before clamping to get proper rounding. In other
-      // case brightness loss will be noticeable if you resize image with white
-      // border and place it on white background.
-      //
-      dest[destOffset] = (r + (1 << 13)) >> FIXED_FRAC_BITS;
-      dest[destOffset + 1] = (g + (1 << 13)) >> FIXED_FRAC_BITS;
-      dest[destOffset + 2] = (b + (1 << 13)) >> FIXED_FRAC_BITS;
-      dest[destOffset + 3] = (a + (1 << 13)) >> FIXED_FRAC_BITS;
-
-      destOffset = (destOffset + sh * 4) | 0;
-    }
-
-    destOffset = ((sourceY + 1) * 4) | 0;
-    srcOffset = ((sourceY + 1) * sw * 4) | 0;
-  }
-}
-
 /**
  * Copy the contents of the source image to the destination image
  * @param source - the source image
@@ -200,7 +132,7 @@ export function convolve(
  * @param dx - destination starting x point [Default: 0]
  * @param dy - destination starting y point [Default: 0]
  */
-export function copy(
+export function copyImage(
   source: ImageData,
   dest: ImageData,
   sx = 0,
@@ -295,7 +227,7 @@ export function createImage(
  * @param dest - the destination image
  * @param use2 - use 2nd lanczos filter instead of 3rd
  */
-export function resize(source: ImageData, dest: ImageData, use2 = false): void {
+export function resizeImage(source: ImageData, dest: ImageData, use2 = false): void {
   const xRatio = dest.width / source.width;
   const yRatio = dest.height / source.height;
 
@@ -304,32 +236,74 @@ export function resize(source: ImageData, dest: ImageData, use2 = false): void {
 
   const tmp = new Uint8ClampedArray(dest.width * source.height * 4);
 
-  convolve(source.data, tmp, source.width, source.height, dest.width, filtersX);
-  convolve(tmp, dest.data, source.height, dest.width, dest.height, filtersY);
+  convolveImage(source.data, tmp, source.width, source.height, dest.width, filtersX);
+  convolveImage(tmp, dest.data, source.height, dest.width, dest.height, filtersY);
 }
 
-/*
-  Adapted to typescript from pica: https://github.com/nodeca/pica
+/**
+ * Convolve an image with a filter
+ * @param source - the source image
+ * @param dest - the destination image
+ * @param sw - source width
+ * @param sh - source height
+ * @param dw - destination width
+ * @param filters - image filter
+ */
+export function convolveImage(
+  source: Uint8ClampedArray,
+  dest: Uint8ClampedArray,
+  sw: number,
+  sh: number,
+  dw: number,
+  filters: Int16Array,
+): void {
+  let srcOffset = 0;
+  let destOffset = 0;
+
+  // For each row
+  for (let sourceY = 0; sourceY < sh; sourceY++) {
+    let filterPtr = 0;
+
+    // Apply precomputed filters to each destination row point
+    for (let destX = 0; destX < dw; destX++) {
+      // Get the filter that determines the current output pixel.
+      const filterShift = filters[filterPtr++];
+
+      let srcPtr = (srcOffset + filterShift * 4) | 0;
+
+      let r = 0;
+      let g = 0;
+      let b = 0;
+      let a = 0;
+
+      // Apply the filter to the row to get the destination pixel r, g, b, a
+      for (let filterSize = filters[filterPtr++]; filterSize > 0; filterSize--) {
+        const filterValue = filters[filterPtr++];
 
-  (The MIT License)
+        r = (r + filterValue * source[srcPtr]) | 0;
+        g = (g + filterValue * source[srcPtr + 1]) | 0;
+        b = (b + filterValue * source[srcPtr + 2]) | 0;
+        a = (a + filterValue * source[srcPtr + 3]) | 0;
 
-  Copyright (C) 2014-2017 by Vitaly Puzrin
+        srcPtr = (srcPtr + 4) | 0;
+      }
 
-  Permission is hereby granted, free of charge, to any person obtaining a copy
-  of this software and associated documentation files (the "Software"), to deal
-  in the Software without restriction, including without limitation the rights
-  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-  copies of the Software, and to permit persons to whom the Software is
-  furnished to do so, subject to the following conditions:
+      // Bring this value back in range. All of the filter scaling factors
+      // are in fixed point with FIXED_FRAC_BITS bits of fractional part.
+      //
+      // (!) Add 1/2 of value before clamping to get proper rounding. In other
+      // case brightness loss will be noticeable if you resize image with white
+      // border and place it on white background.
+      //
+      dest[destOffset] = (r + (1 << 13)) >> FIXED_FRAC_BITS;
+      dest[destOffset + 1] = (g + (1 << 13)) >> FIXED_FRAC_BITS;
+      dest[destOffset + 2] = (b + (1 << 13)) >> FIXED_FRAC_BITS;
+      dest[destOffset + 3] = (a + (1 << 13)) >> FIXED_FRAC_BITS;
 
-  The above copyright notice and this permission notice shall be included in
-  all copies or substantial portions of the Software.
+      destOffset = (destOffset + sh * 4) | 0;
+    }
 
-  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-  THE SOFTWARE.
-*/
+    destOffset = ((sourceY + 1) * 4) | 0;
+    srcOffset = ((sourceY + 1) * sw * 4) | 0;
+  }
+}

src/util/index.ts

@@ -1,4 +1,5 @@
 export * from './gzip';
+export * from './image';
 export * from './lzw';
 
 /** The formats available to DecompressionStream */

tests/tools/lanczos/index.test.ts

@@ -1,4 +1,4 @@
-import { createImage, lanczos } from '../../../src/tools/lanczos';
+import { createImage, lanczos } from '../../../src';
 import { expect, test } from 'bun:test';
 
 import sharp from 'sharp';