PDF to Image Ruby Examples

Complete Ruby examples for common PDF to Image tasks. See the Ruby SDK guide for installation and result handling.

You can run the examples below with the displayed API credentials. Update the input URLs and filenames as needed. Each Ruby example can be copied and run independently.

Basic examples

Choose file, in-memory, or output-stream handling for the ZIP archive. Stream examples use a binary file stream as their destination.

These basic examples produce a ZIP archive containing PNG images of the PDF pages. The archive variable holds ZIP bytes in the memory variants.

Convert a PDF file

Upload an existing invoice.pdf file.

Save to a file

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setForceZip(true)
client.setOutputFormat('png')
client.convertFileToFile('invoice.pdf', 'invoice.zip')

Keep in memory

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setForceZip(true)
client.setOutputFormat('png')
archive = client.convertFile('invoice.pdf') # binary String
puts archive.bytesize

Write to a stream

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

File.open('invoice.zip', 'wb') do |output_stream|
  client.setForceZip(true)
  client.setOutputFormat('png')
  client.convertFileToStream('invoice.pdf', output_stream)
end

Convert a URL

Fetch a PDF from its URL.

Save to a file

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setForceZip(true)
client.setOutputFormat('png')
client.convertUrlToFile('https://your-server.com/invoice.pdf', 'invoice.zip')

Keep in memory

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setForceZip(true)
client.setOutputFormat('png')
archive = client.convertUrl('https://your-server.com/invoice.pdf') # binary String
puts archive.bytesize

Write to a stream

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

File.open('invoice.zip', 'wb') do |output_stream|
  client.setForceZip(true)
  client.setOutputFormat('png')
  client.convertUrlToStream(
    'https://your-server.com/invoice.pdf', output_stream
  )
end

Convert raw PDF bytes

Read invoice.pdf as binary data. In an application, pass the bytes you already hold in memory instead.

Save to a file

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

pdf_data_1 = File.binread('invoice.pdf') # binary String
client.setForceZip(true)
client.setOutputFormat('png')
client.convertRawDataToFile(pdf_data_1, 'invoice.zip')

Keep in memory

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

pdf_data_1 = File.binread('invoice.pdf') # binary String
client.setForceZip(true)
client.setOutputFormat('png')
archive = client.convertRawData(pdf_data_1) # binary String
puts archive.bytesize

Write to a stream

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

File.open('invoice.zip', 'wb') do |output_stream|
  pdf_data_1 = File.binread('invoice.pdf') # binary String
  client.setForceZip(true)
  client.setOutputFormat('png')
  client.convertRawDataToStream(pdf_data_1, output_stream)
end

Read from an input stream

Open invoice.pdf as a binary input stream and save the result to invoice.zip.

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

File.open('invoice.pdf', 'rb') do |input_stream|
  client.setForceZip(true)
  client.setOutputFormat('png')
  client.convertStreamToFile(input_stream, 'invoice.zip')
end

Customize page images

These examples use report.pdf, a three-page document with text, a chart, and vector graphics. The CropBox variant uses cropbox.pdf, a page with a predefined crop boundary.

Create page previews

Render page 1 of report.pdf directly as a PNG. Use 72 DPI for a compact preview or 300 DPI for more detail at higher pixel dimensions and file size. Selecting one page produces an image file without ZIP packaging.

Compact preview at 72 DPI

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setDpi(72)
client.setOutputFormat('png')
client.setPrintPageRange('1')
client.convertFileToFile('report.pdf', 'preview.png')

High-resolution image at 300 DPI

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setDpi(300)
client.setOutputFormat('png')
client.setPrintPageRange('1')
client.convertFileToFile('report.pdf', 'page-300dpi.png')

Render selected pages

Render pages 1 and 3 of report.pdf as PNG images in selected-pages.zip. Force ZIP packaging so the result stays an archive even if you later select just one page.

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setForceZip(true)
client.setOutputFormat('png')
client.setPrintPageRange('1,3')
client.convertFileToFile('report.pdf', 'selected-pages.zip')

Export a JPEG

Convert page 1 of report.pdf into page.jpg for applications that need JPEG input. JPEG is lossy and is not always smaller than PNG, especially for pages dominated by text and flat graphics.

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setOutputFormat('jpg')
client.setPrintPageRange('1')
client.convertFileToFile('report.pdf', 'page.jpg')

Crop page images

Extract the chart from page 1 of report.pdf into chart.png, or honor the predefined CropBox in cropbox.pdf to remove its production margins.

The chart example fixes 144 DPI and uses pixel coordinates from the rendered page's top-left corner: X = 96, Y = 370, width = 1024, height = 384. Adjust the coordinates when changing the page layout or DPI. The CropBox variant uses the boundary already stored in the PDF.

Extract a chart region

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setCropAreaHeight(384)
client.setCropAreaWidth(1024)
client.setCropAreaX(96)
client.setCropAreaY(370)
client.setDpi(144)
client.setOutputFormat('png')
client.setPrintPageRange('1')
client.convertFileToFile('report.pdf', 'chart.png')

Use the PDF's CropBox

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setOutputFormat('png')
client.setPrintPageRange('1')
client.setUseCropbox(true)
client.convertFileToFile('cropbox.pdf', 'cropped-page.png')

Create a grayscale image

Render page 1 of report.pdf into grayscale.png, replacing colors with shades of gray while preserving the page dimensions.

require 'pdfcrowd'

client = Pdfcrowd::PdfToImageClient.new('demo', 'demo')

client.setOutputFormat('png')
client.setPrintPageRange('1')
client.setUseGrayscale(true)
client.convertFileToFile('report.pdf', 'grayscale.png')