Image to Image API - Node.js SDK

Convert between various image formats in Node.js using the Pdfcrowd API v2. The API is easy to use and the integration takes only a couple of lines of code.

Installation

Install the client library from npm
npm install pdfcrowd

You can learn more about other install options here.

Authentication

Authentication is needed in order to use the Pdfcrowd API. The credentials used for accessing the API are your Pdfcrowd username and the API key. You can sign up for the Pdfcrowd API here.

Examples

Convert a local PNG file to a JPEG file
var pdfcrowd = require("pdfcrowd");

// create the API client instance
var client = new pdfcrowd.ImageToImageClient("your_username", "your_apikey");

// configure the conversion
try {
    client.setOutputFormat("jpg");
} catch(why) {
    console.error("Pdfcrowd Error: " + why);
    console.error("Pdfcrowd Error Code: " + why.getCode());
    console.error("Pdfcrowd Error Message: " + why.getMessage());
    process.exit(1);
}

// run the conversion and write the result to a file
client.convertFileToFile(
    "/path/to/logo.png",
    "logo.jpg",
    function(err, fileName) {
        if (err) return console.error("Pdfcrowd Error: " + err);
        console.log("Success: the file was created " + fileName);
    });
Convert a local PNG file to a JPEG file via custom callbacks
var pdfcrowd = require("pdfcrowd");

// create the API client instance
var client = new pdfcrowd.ImageToImageClient("your_username", "your_apikey");

// configure the conversion
try {
    client.setOutputFormat("jpg");
} catch(why) {
    console.error("Pdfcrowd Error: " + why);
    console.error("Pdfcrowd Error Code: " + why.getCode());
    console.error("Pdfcrowd Error Message: " + why.getMessage());
    process.exit(1);
}

// use predefined callback for saving to a file
var callbacks = pdfcrowd.saveToFile("logo.jpg");

// set custom error callback
callbacks.error = function(errMessage, statusCode) {
    if(statusCode) {
        console.error("Pdfcrowd Error: " + statusCode + " - " + errMessage);
    } else {
        console.error("Pdfcrowd Error: " + errMessage);
    }
};

// run the conversion and write the result to a file
client.convertFile("/path/to/logo.png", callbacks);
Convert url with PNG file to a JPEG file
var pdfcrowd = require("pdfcrowd");

// create the API client instance
var client = new pdfcrowd.ImageToImageClient("your_username", "your_apikey");

// configure the conversion
try {
    client.setOutputFormat("jpg");
} catch(why) {
    console.error("Pdfcrowd Error: " + why);
    console.error("Pdfcrowd Error Code: " + why.getCode());
    console.error("Pdfcrowd Error Message: " + why.getMessage());
    process.exit(1);
}

// run the conversion and write the result to a file
client.convertUrlToFile(
    "http://pdfcrowd.com/static/images/logo.png",
    "logo.jpg",
    function(err, fileName) {
        if (err) return console.error("Pdfcrowd Error: " + err);
        console.log("Success: the file was created " + fileName);
    });
Convert url with PNG file to a JPEG file via custom callbacks
var pdfcrowd = require("pdfcrowd");

// create the API client instance
var client = new pdfcrowd.ImageToImageClient("your_username", "your_apikey");

// configure the conversion
try {
    client.setOutputFormat("jpg");
} catch(why) {
    console.error("Pdfcrowd Error: " + why);
    console.error("Pdfcrowd Error Code: " + why.getCode());
    console.error("Pdfcrowd Error Message: " + why.getMessage());
    process.exit(1);
}

// use predefined callback for saving to a file
var callbacks = pdfcrowd.saveToFile("logo.jpg");

// set custom error callback
callbacks.error = function(errMessage, statusCode) {
    if(statusCode) {
        console.error("Pdfcrowd Error: " + statusCode + " - " + errMessage);
    } else {
        console.error("Pdfcrowd Error: " + errMessage);
    }
};

// run the conversion and write the result to a file
client.convertUrl("http://pdfcrowd.com/static/images/logo.png", callbacks);
Convert an in-memory PNG to a JPEG file
var pdfcrowd = require("pdfcrowd");
var fs = require("fs");

// create the API client instance
var client = new pdfcrowd.ImageToImageClient("your_username", "your_apikey");

// configure the conversion
try {
    client.setOutputFormat("jpg");
} catch(why) {
    console.error("Pdfcrowd Error: " + why);
    console.error("Pdfcrowd Error Code: " + why.getCode());
    console.error("Pdfcrowd Error Message: " + why.getMessage());
    process.exit(1);
}

// run the conversion and write the result to a file
client.convertRawDataToFile(
    fs.readFileSync("/path/to/logo.png"),
    "logo.jpg",
    function(err, fileName) {
        if (err) return console.error("Pdfcrowd Error: " + err);
        console.log("Success: the file was created " + fileName);
    });
Convert an in-memory PNG to a JPEG file via custom callbacks
var pdfcrowd = require("pdfcrowd");
var fs = require("fs");

// create the API client instance
var client = new pdfcrowd.ImageToImageClient("your_username", "your_apikey");

// configure the conversion
try {
    client.setOutputFormat("jpg");
} catch(why) {
    console.error("Pdfcrowd Error: " + why);
    console.error("Pdfcrowd Error Code: " + why.getCode());
    console.error("Pdfcrowd Error Message: " + why.getMessage());
    process.exit(1);
}

// use predefined callback for saving to a file
var callbacks = pdfcrowd.saveToFile("logo.jpg");

// set custom error callback
callbacks.error = function(errMessage, statusCode) {
    if(statusCode) {
        console.error("Pdfcrowd Error: " + statusCode + " - " + errMessage);
    } else {
        console.error("Pdfcrowd Error: " + errMessage);
    }
};

// run the conversion and write the result to a file
client.convertRawData(fs.readFileSync("/path/to/logo.png"), callbacks);
Get info about the current conversion
var pdfcrowd = require("pdfcrowd");

// create the API client instance
var client = new pdfcrowd.ImageToImageClient("your_username", "your_apikey");

// configure the conversion
try {
    client.setOutputFormat("jpg");
    client.setDebugLog(true);
} catch(why) {
    console.error("Pdfcrowd Error: " + why);
    console.error("Pdfcrowd Error Code: " + why.getCode());
    console.error("Pdfcrowd Error Message: " + why.getMessage());
    process.exit(1);
}

// run the conversion and write the result to a file
client.convertFileToFile(
    "/path/to/logo.png",
    "logo.jpg",
    function(err, fileName) {
        if (err) return console.error("Pdfcrowd Error: " + err);
        console.log("Success: the file was created " + fileName);
        
        // print URL to the debug log
        console.log("Debug log url: " + client.getDebugLogUrl());
        
        // print the number of available conversion credits in your account
        console.log("Remaining credit count: " + client.getRemainingCreditCount());
        
        // print the number of credits consumed by the conversion
        console.log("Consumed credit count: " + client.getConsumedCreditCount());
        
        // print the unique ID of the conversion
        console.log("Job id: " + client.getJobId());
        
        // print the size of the output in bytes
        console.log("Output size: " + client.getOutputSize());
    });

Tips & Tricks

API Reference - class ImageToImageClient

Conversion from one image format to another image format.

Constructor

function ImageToImageClient(userName, apiKey)
Constructor for the Pdfcrowd API client.
Parameter Description Default
userName
Your username at Pdfcrowd.
apiKey
Your API key.

 

Conversion Input

function convertUrl(url, callbacks)
Convert an image.
Parameter Description Default
url
The address of the image to convert.
The supported protocols are http:// and https://.
callbacks
The object that defines the following functions:
  • data(readStream) - called when the output data can be read from readStream
  • error(message, statusCode) - called when an error occurs
  • end() - called when the conversion finishes
The client library provides 2 helper functions that can be used here:
  • saveToFile(filePath[, callback]) - saves the output data to a file
    • filePath - the output file path
    • callback(err, filePath) - called when the conversion finishes
  • sendImageInHttpResponse(response, contentType, fileName[, disposition]) - sends the generated image in an HTTP response
    • response - the response object
    • contentType - the response content type
    • fileName - the desired file name
    • disposition - the response content disposition, can be "attachment" or "inline", the default is "attachment".
function convertUrlToFile(url, filePath, callback)
Convert an image and write the result to a local file.
Parameter Description Default
url
The address of the image to convert.
The supported protocols are http:// and https://.
filePath
The output file path.
The string must not be empty.
callback
The callback(error, filePath) function is called when the conversion finishes. The error object is present if an error occurred, filePath is the output file path.
function convertFile(file, callbacks)
Convert a local file.
Parameter Description Default
file
The path to a local file to convert.
The file can be either a single file or an archive (.tar.gz, .tar.bz2, or .zip).
The file must exist and not be empty.
callbacks
The object that defines the following functions:
  • data(readStream) - called when the output data can be read from readStream
  • error(message, statusCode) - called when an error occurs
  • end() - called when the conversion finishes
The client library provides 2 helper functions that can be used here:
  • saveToFile(filePath[, callback]) - saves the output data to a file
    • filePath - the output file path
    • callback(err, filePath) - called when the conversion finishes
  • sendImageInHttpResponse(response, contentType, fileName[, disposition]) - sends the generated image in an HTTP response
    • response - the response object
    • contentType - the response content type
    • fileName - the desired file name
    • disposition - the response content disposition, can be "attachment" or "inline", the default is "attachment".
function convertFileToFile(file, filePath, callback)
Convert a local file and write the result to a local file.
Parameter Description Default
file
The path to a local file to convert.
The file can be either a single file or an archive (.tar.gz, .tar.bz2, or .zip).
The file must exist and not be empty.
filePath
The output file path.
The string must not be empty.
callback
The callback(error, filePath) function is called when the conversion finishes. The error object is present if an error occurred, filePath is the output file path.
function convertRawData(data, callbacks)
Convert raw data.
Parameter Description Default
data
The raw content to be converted.
callbacks
The object that defines the following functions:
  • data(readStream) - called when the output data can be read from readStream
  • error(message, statusCode) - called when an error occurs
  • end() - called when the conversion finishes
The client library provides 2 helper functions that can be used here:
  • saveToFile(filePath[, callback]) - saves the output data to a file
    • filePath - the output file path
    • callback(err, filePath) - called when the conversion finishes
  • sendImageInHttpResponse(response, contentType, fileName[, disposition]) - sends the generated image in an HTTP response
    • response - the response object
    • contentType - the response content type
    • fileName - the desired file name
    • disposition - the response content disposition, can be "attachment" or "inline", the default is "attachment".
function convertRawDataToFile(data, filePath, callback)
Convert raw data to a file.
Parameter Description Default
data
The raw content to be converted.
filePath
The output file path.
The string must not be empty.
callback
The callback(error, filePath) function is called when the conversion finishes. The error object is present if an error occurred, filePath is the output file path.

 

Conversion Format

function setOutputFormat(outputFormat)
The format of the output file.
Parameter Description Default
outputFormat
Allowed values:
  • png
  • jpg
  • gif
  • tiff
  • bmp
  • ico
  • ppm
  • pgm
  • pbm
  • pnm
  • psb
  • pct
  • ras
  • tga
  • sgi
  • sun
  • webp
png
Returns
  • ImageToImageClient - The converter object.

 

Image operations

Settings used for operations with images.

function setResize(resize)
Resize the image.
Parameter Description Default
resize
The resize percentage or new image dimensions.
100%
Returns
  • ImageToImageClient - The converter object.
Examples:
  • setResize("200%")
  • setResize("1024x768")
function setRotate(rotate)
Rotate the image.
Parameter Description Default
rotate
The rotation specified in degrees.
0
Returns
  • ImageToImageClient - The converter object.

 

Miscellaneous

function setDebugLog(debugLog)
Turn on the debug logging. Details about the conversion are stored in the debug log. The URL of the log can be obtained from the getDebugLogUrl method.
Parameter Description Default
debugLog
Set to true to enable the debug logging.
false
Returns
  • ImageToImageClient - The converter object.
function getDebugLogUrl()
Get the URL of the debug log for the last conversion.
Returns
  • string - The link to the debug log.
function getRemainingCreditCount()
Get the number of conversion credits available in your account.
The returned value can differ from the actual count if you run parallel conversions.
The special value 999999 is returned if the information is not available.
Returns
  • int - The number of credits.
function getConsumedCreditCount()
Get the number of credits consumed by the last conversion.
Returns
  • int - The number of credits.
function getJobId()
Get the job id.
Returns
  • string - The unique job identifier.
function getOutputSize()
Get the size of the output in bytes.
Returns
  • int - The count of bytes.
function setTag(tag)
Tag the conversion with a custom value. The tag is used in conversion statistics. A value longer than 32 characters is cut off.
Parameter Description Default
tag
A string with the custom tag.
Returns
  • ImageToImageClient - The converter object.

 

API Client Options

function setUseHttp(useHttp)
Specifies if the client communicates over HTTP or HTTPS with Pdfcrowd API.
Parameter Description Default
useHttp
Set to true to use HTTP.
false
Returns
  • ImageToImageClient - The converter object.
function setUserAgent(userAgent)
Set a custom user agent HTTP header. It can be usefull if you are behind some proxy or firewall.
Parameter Description Default
userAgent
The user agent string.
pdfcrowd_nodejs_client/4.3.5 (http://pdfcrowd.com)
Returns
  • ImageToImageClient - The converter object.
function setProxy(host, port, userName, password)
Specifies an HTTP proxy that the API client library will use to connect to the internet.
Parameter Description Default
host
The proxy hostname.
port
The proxy port.
userName
The username.
password
The password.
Returns
  • ImageToImageClient - The converter object.
function setRetryCount(retryCount)
Specifies the number of retries when the 502 HTTP status code is received. The 502 status code indicates a temporary network issue. This feature can be disabled by setting to 0.
Parameter Description Default
retryCount
Number of retries wanted.
1
Returns
  • ImageToImageClient - The converter object.

 

Error Handling

try {
    // call the API 
}
catch(why) {
    // print error
    console.error("Pdfcrowd Error: " + why);

    // print just error code
    console.error("Pdfcrowd Error Code: " + why.getCode());

    // print just error message
    console.error("Pdfcrowd Error Message: " + why.getMessage());

    // or handle the error by your way
}

Troubleshooting