Stirling-PDF/shared-operations/src/functions/removeBlankPages.ts

import { PdfFile } from '../wrappers/PdfFile.js';
import { detectEmptyPages } from './common/detectEmptyPages.js';
import { getPages } from './common/getPagesByIndex.js';
import { invertSelection } from './common/pageIndexesUtils.js';

export type RemoveBlankPagesParamsType = {
    file: PdfFile;
    whiteThreashold: number;
}
export async function removeBlankPages(params: RemoveBlankPagesParamsType) {
    const { file, whiteThreashold } = params;
    const pageCount = await file.pdfLibDocument;

    const emptyPages = await detectEmptyPages(file, whiteThreashold);
    console.debug("Empty Pages: ", emptyPages);
    const pagesToKeep = invertSelection(emptyPages, pageCount.getPageCount())

    const newFile = await getPages(file, pagesToKeep);
    newFile.filename += "_removedBlanks"
    return newFile;
}