pixel-utils/dist/esm/fit/index.js

Utility Functions for Pixels

import { prepareData, prepareUpdate } from "xdim";
import rawToRgba from "../raw-to-rgba";
import selectPixel from "../select-pixel";
// fit raw bands to 8-bit color space
// while slicing and scaling as necessary
export default function fit({
  data,
  debug_level = 0,
  depth,
  flip = false,
  old_no_data_value,
  old_layout,
  no_data_strategy = "partial",
  // png strategy
  no_range_value,
  no_range_value_strategy = "top",
  new_layout = "[row,column,band]",
  new_no_data_value,
  height,
  ranges,
  width
}) {
  if (!ranges) throw new Error("[expand] can't expand without ranges");
  if (debug_level >= 1) console.log("[stretch] starting fit");
  if (typeof height !== "number") throw new Error("[fit] height must be a number");
  if (typeof width !== "number") throw new Error("[fit] height must be a number");
  if (typeof old_layout !== "string") throw new Error("[fit] old_layout must be a string");
  if (typeof new_layout !== "string") throw new Error("[fit] new_layout must be a string");
  const select = selectPixel(data, {
    depth,
    height,
    layout: old_layout,
    width
  });
  const out_sizes = {
    band: 4,
    row: height,
    column: width
  };
  const {
    data: out_data
  } = prepareData({
    fill: new_no_data_value,
    layout: new_layout,
    sizes: out_sizes
  });
  const convert = rawToRgba({
    debug_level: debug_level - 1,
    format: "array",
    flip,
    ranges,
    new_no_data_value: new_no_data_value,
    no_data_strategy: no_data_strategy,
    no_range_value: no_range_value,
    no_range_value_strategy: no_range_value_strategy,
    old_no_data_value
  });
  const update = prepareUpdate({
    data: out_data,
    layout: new_layout,
    sizes: out_sizes
  });
  for (let row = 0; row < height; row++) {
    for (let column = 0; column < width; column++) {
      const [r, g, b, a] = convert(select(row, column));
      update({
        point: {
          band: 0,
          row,
          column
        },
        value: r
      });
      update({
        point: {
          band: 1,
          row,
          column
        },
        value: g
      });
      update({
        point: {
          band: 2,
          row,
          column
        },
        value: b
      });
      update({
        point: {
          band: 3,
          row,
          column
        },
        value: a
      });
    }
  }
  if (debug_level >= 1) console.log("[pixel-utils/fit] out_data:", out_data);
  return {
    // @ts-ignore
    data: out_data,
    layout: new_layout
  };
}