(Feature) Ability to specify target file size for PDF compression

[user1823]

Feature Description

While compressing PDFs, an option to specify the target file size.

Use Case

The Problem
I had a 1.1 MB PDF file. I had to compress it to a size below 200 KB for uploading somewhere. With BentoPDF's aggressive mode, I got a 380 KB file (which was larger than I needed) and with extreme mode, I got an 82 KB file (which had a very low quality and consequently, it was not usable).

The Solution
BentoPDF can expose a target file size option, similar to several other online PDF compression websites.

Examples

An open-source alternative: https://github.com/Stirling-Tools/Stirling-PDF

(Stirling PDF)

You may want to refer to its source code to see how Stirling PDF implements this feature:

CompressController.java#L973-L976:

            if (autoMode) {
                double sizeReductionRatio = expectedOutputSize / (double) inputFileSize;
                optimizeLevel = determineOptimizeLevel(sizeReductionRatio);
            }

CompressController.java#L1064-L1082:

                // Check if target size reached or not in auto mode
                long outputFileSize = Files.size(currentFile);
                if (outputFileSize <= expectedOutputSize || !autoMode) {
                    sizeMet = true;
                } else {
                    int newOptimizeLevel =
                            incrementOptimizeLevel(
                                    optimizeLevel, outputFileSize, expectedOutputSize);


                    // Check if we can't increase the level further
                    if (newOptimizeLevel == optimizeLevel) {
                        log.info("Maximum optimization level reached without meeting target size.");
                        sizeMet = true;
                    } else {
                        // Reset flags for next iteration with higher optimization level
                        imageCompressionApplied = false;
                        optimizeLevel = newOptimizeLevel;
                    }
                }

Additional Context

No response

[user1823]

I used Claude to generate a Python script (compress_pdf.py) combining optimization techniques from BentoPDF, PDF4QT and Stirling PDF. It seems to work really well. You may want to have a look.

[alam00000]

Sure, that will be added. Thank you

[mondeep31]

@alam00000 hey, have you planned anything for this feature? if you wish to add this, let me know, i can work on it.