Tesseract OCR on Golem

OCR Images using Tesseract by leveraging Golem Network's computation resources.

Features

• 🔍 Runs Tesseract OCR on files which you provide to convertImageToText method.
• 🌐 Leverages Golem Network's computing capacity
• 💰 Simplifies pricing for compute resources you provide the specification of your needs with the minimum amount of input required.
• ⚖ Scales resources dynamically
  • Acquires compute resources and scales up the number of OCR instances in response to the request load to a configured maximum.
  • Releases compute resources unused for at least 30 seconds, down-scaling automatically for cost-saving.

Installation

Installing Tesseract OCR on Golem library

You can install this library using your favourite package manager:

npm install --save tesseract-ocr-golem

Joining the Golem Network as requestor

In order to run workloads on Golem Network, you need to join as a requestor. If you're working on a linux system, it's a simple bash-line. For more installation instructions, visit the Official JS SDK QuickStart.

curl -sSf https://join.golem.network/as-requestor | bash -

After installing Golem Network software (yagna), you can obtain your API key which you will use with the library:

yagna app-key list

Usage

Here's an example of a working script that will allow you to send example images to OCR on the Golem Network using Tesseract OCR image.

import * as fs from "fs";
import { TesseractOcrOnGolem } from "tesseract-ocr-golem";

/**
 * Utility used to write down results
 *
 * @param text The resulting text if any present
 */
const writeTextToResultFile = (text?: string) => {
  if (text) {
    fs.writeFileSync(`./examples/out/results.txt`, text, { flag: "a" });
  }
};

(async () => {
  const ocr = new TesseractOcrOnGolem({
    service: {
      market: {
        rentHours: 0.5,
        priceGlmPerHour: 1.0,
      },
      deploy: {
        maxReplicas: 4,
        resources: {
          minCpuThreads: 2,
          maxCpuThreads: 4,
        },
        downscaleIntervalSec: 60,
      },
      initTimeoutSec: 90,
      requestStartTimeoutSec: 30,
    },
    args: {
      lang: "eng",
    },
  });

  try {
    // Power-on the OCR, get the resources on Golem Network
    // This will wait until the resources are found and the OCR is ready to use
    await ocr.init();

    // Do your work
    console.log("Starting work for my customers...");
    const texts = await Promise.all([
      ocr.convertImageToText("./examples/data/img.png"),
      ocr.convertImageToText("./examples/data/5W40s.png"),
      ocr.convertImageToText("./examples/data/msword_text_rendering.png"),
      ocr.convertImageToText("./examples/data/poem.png"),
    ]);

    texts.forEach(writeTextToResultFile);

    console.log("Work done, going to bill my customers...");
    // TODO: Bill your customers ;)
  } catch (err) {
    console.error(err, "Failed to run the OCR on Golem");
  } finally {
    await ocr.shutdown();
  }
})().catch((err) => console.error(err, "Error in main"));

Configuration

Supported environment variables

Operating on the Golem Network requires

Env variable	Required	Default value	Description
GOLEM_API_KEY	yes		Yagna app-key used to identify your application
GOLEM_API_URL	no	http://localhost:7465	Where is your yagna instance located
GOLEM_PAYMENT_NETWORK	no	holesky	On which network you want to get the compute resources. polygon is the main network, where the real GLM tokens are used. holesky is the default test network.

The configuration object

The config object accepted by TesseractOcrOnGolem can be composed of 2 properties:

• args which control the default parameters which will be passed to tesseract when running the OCR (see docs)
• service which control the deployment of the OCR instances on the Golem Network (see docs)

For details regarding specific config options, please refer to the API Documentation.

Debugging

If you want to know what's going on inside the library, including logs from @golem-sdk/golem-js you can use the DEBUG environment variable to see verbose logs. This library makes use of the debug package to implement logs. If you want to fine-tune the log output, please refer to the library's documentation.

Most of the time, such a line should suffice:

DEBUG="golem-js:*,golem,tesseract" GOLEM_API_KEY="your-api-key-to-yagna" npm run example

See also

• Golem JS SDK official repo and documentation.