Image to PDF Ruby Examples

Complete Ruby examples for common Image to PDF 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 PDF result. Stream examples use a binary file stream as their destination.

Convert an image file

Upload an existing logo.png file.

Save to a file

require 'pdfcrowd'

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

client.convertFileToFile('logo.png', 'logo.pdf')

Keep in memory

require 'pdfcrowd'

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

pdf = client.convertFile('logo.png') # binary String
puts pdf.bytesize

Write to a stream

require 'pdfcrowd'

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

File.open('logo.pdf', 'wb') do |output_stream|
  client.convertFileToStream('logo.png', output_stream)
end

Convert a URL

Fetch an image from its URL.

Save to a file

require 'pdfcrowd'

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

client.convertUrlToFile('https://your-server.com/logo.png', 'logo.pdf')

Keep in memory

require 'pdfcrowd'

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

pdf = client.convertUrl('https://your-server.com/logo.png') # binary String
puts pdf.bytesize

Write to a stream

require 'pdfcrowd'

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

File.open('logo.pdf', 'wb') do |output_stream|
  client.convertUrlToStream('https://your-server.com/logo.png', output_stream)
end

Convert raw image bytes

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

Save to a file

require 'pdfcrowd'

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

image_data_1 = File.binread('logo.png') # binary String
client.convertRawDataToFile(image_data_1, 'logo.pdf')

Keep in memory

require 'pdfcrowd'

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

image_data_1 = File.binread('logo.png') # binary String
pdf = client.convertRawData(image_data_1) # binary String
puts pdf.bytesize

Write to a stream

require 'pdfcrowd'

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

File.open('logo.pdf', 'wb') do |output_stream|
  image_data_1 = File.binread('logo.png') # binary String
  client.convertRawDataToStream(image_data_1, output_stream)
end

Read from an input stream

Open logo.png as a binary input stream and save the result to logo.pdf.

require 'pdfcrowd'

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

File.open('logo.png', 'rb') do |input_stream|
  client.convertStreamToFile(input_stream, 'logo.pdf')
end

Customize the PDF

These examples use scan.png, a 1224 × 1584 pixel image with text, a chart, and a uniform white border. The rotation example uses its sideways variant, scan-sideways.png.

Fit an image onto paper

Fit the whole image onto A4 portrait or Letter landscape paper with 12mm margins and 150 DPI. The fit mode preserves the image's aspect ratio. Setting a page size without it can clip a larger image.

A4 portrait

require 'pdfcrowd'

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

client.setDpi(150)
client.setMarginBottom('12mm')
client.setMarginLeft('12mm')
client.setMarginRight('12mm')
client.setMarginTop('12mm')
client.setPageSize('A4')
client.setPrintPageMode('fit')
client.convertFileToFile('scan.png', 'a4.pdf')

Letter landscape

require 'pdfcrowd'

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

client.setDpi(150)
client.setMarginBottom('12mm')
client.setMarginLeft('12mm')
client.setMarginRight('12mm')
client.setMarginTop('12mm')
client.setOrientation('landscape')
client.setPageSize('Letter')
client.setPrintPageMode('fit')
client.convertFileToFile('scan.png', 'landscape.pdf')

Create a custom-size PDF

Fit scan.png onto a 4 × 6 inch page and save custom-page.pdf. Preserve the aspect ratio and fill the unused page area with a pale blue background.

require 'pdfcrowd'

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

client.setDpi(150)
client.setPageBackgroundColor('EEF2F6')
client.setPageHeight('6in')
client.setPageWidth('4in')
client.setPrintPageMode('fit')
client.convertFileToFile('scan.png', 'custom-page.pdf')

Interpret scan.png at 300 pixels per inch without setting a fixed page size. Its 1224 × 1584 pixels produce a 4.08 × 5.28 inch page in print-size.pdf, with the original image pixels retained.

require 'pdfcrowd'

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

client.setDpi(300)
client.convertFileToFile('scan.png', 'print-size.pdf')

Crop or trim an image

Extract the chart from scan.png into chart.pdf, or remove its uniform outer border and save trimmed.pdf.

The chart starts 96 pixels from the left and 370 pixels from the top, and measures 1024 × 384 pixels. Set 96 DPI so the px crop coordinates match the source image pixels; adjust the region for your image. Automatic border removal works on solid-color borders; use an explicit crop for uneven scan edges.

Extract a selected region

require 'pdfcrowd'

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

client.setCropAreaHeight('384px')
client.setCropAreaWidth('1024px')
client.setCropAreaX('96px')
client.setCropAreaY('370px')
client.setDpi(96)
client.convertFileToFile('scan.png', 'chart.pdf')

Remove a uniform border

require 'pdfcrowd'

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

client.setDpi(150)
client.setRemoveBorders(true)
client.convertFileToFile('scan.png', 'trimmed.pdf')

Correct image rotation

Rotate scan-sideways.png 90 degrees clockwise to restore the upright orientation, then save upright.pdf.

require 'pdfcrowd'

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

client.setDpi(150)
client.setRotate('90')
client.convertFileToFile('scan-sideways.png', 'upright.pdf')

Create a smaller PDF

Render scan.png onto A4 paper at 72 DPI and save compact.pdf. Keep the same fit and 12mm margins as the 150 DPI A4 example above, while reducing resolution for screen viewing. Smaller files come at the cost of fine detail.

require 'pdfcrowd'

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

client.setDpi(72)
client.setMarginBottom('12mm')
client.setMarginLeft('12mm')
client.setMarginRight('12mm')
client.setMarginTop('12mm')
client.setPageSize('A4')
client.setPrintPageMode('fit')
client.convertFileToFile('scan.png', 'compact.pdf')