# ImageCodec : Multi-format image encoder and decoder

This module provides codecs that support multiple formats of image. Currently supported image formats include: 'PNG', 'JPG', 'BMP', 'TGA', 'HDR'.

User can use the following code to import the imagecodec module.

var imagecodec = require('imagecodec');

# Support

The following shows imagecodec module APIs available for each permissions.

# ImageCodec Module

# imagecodec.decode(path[, opt])

• path {String} Image file path.
• opt {Object} Decode options.
• Returns: {Object} Image pixel object.

Decode the specified image and return the image pixel data.

The image decoding opt parameter can contain the following members:

• components {Integer} Image components.

Valid components can choose the following definitions:

The returned object contains the following members:

• width {Integer} Image width.
• height {Integer} Image height.
• components {Integer} Image components bytes.
• buffer {Buffer} Image pixel data buffer.

# Example

var image = imagecodec.decode('./test.png');

# imagecodec.decode(buffer[, opt])

• buffer {Buffer} Image file data buffer.
• opt {Object} Decode options.
• Returns: {Object} Image pixel object.

Decode the specified image and return the image pixel data.

# Example

var image = imagecodec.decode(buffer);

# imagecodec.encode(image, path[, opt])

• image {Object} Image pixel object.
• path {String} Destination path.
• opt {Object} Encode options.
• Returns: {Boolean} Whether the operation was successful.

Compress the original pixel data of the image and store it in the specified path.

The image object must contain the following members:

• width {Integer} Image width.
• height {Integer} Image height.
• components {Integer} Image components bytes.
• buffer {Buffer} Image pixel data buffer.

The path parameter determines the image encoding format, it must contain the file extensions supported by the current module, they include: '*.jpg', '*.png', '*.bmp', '*.tga', '*.hdr'.

The opt parameter is optional, it can contain the following members:

• stride {Integer} If the target is in PNG format, the number of stride bytes can be specified here, please refer to hereopen in new window for details.
• quality {Integer} If the target is JPEG format, quality can be specified here, optional range: 1 ~ 100. default: 70.

# Example

imagecodec.encode(image, './test.jpg', { quality: 80 });

# imagecodec.encode(image, format[, opt])

• image {Object} Image pixel object.
• format {String} Image format.
• opt {Object} Encode options.
• Returns: {Buffer} Image data after encoding.

Compress the original pixel data of the image and store it in buffer.

format specifies the image encoding format, currently supported encoding formats include: 'jpg', 'png', 'bmp', 'tga', 'hdr'.

# Example

var buf = imagecodec.encode(image, 'jpg', { quality: 80 });

# imagecodec.resize(image, dest)

• image {Object} Source image pixel object.
• dest {Object} The image size you want to convert to.
• Returns: {Object} Image pixel object.

Image conversion.

The image object must contain the following members:

• width {Integer} Image width.
• height {Integer} Image height.
• components {Integer} Image components bytes.
• buffer {Buffer} Image pixel data buffer.

The dest object must contain the following members:

• width {Integer} Image width.
• height {Integer} Image height.
• components {Integer} Image components bytes.

The returned object contains the following members:

• width {Integer} Image width.
• height {Integer} Image height.
• components {Integer} Image components bytes.
• buffer {Buffer} Image pixel data buffer.

# Example

var newImage = imagecodec.resize(image, {
  width: 640,
  height: 480,
  components: imagecodec.COMPONENTS_GREY
});

# imagecodec.info(path)

• path {String} Image file path.
• Returns: {Object} Image pixel object.

Get image size information.

The returned object contains the following members:

• width {Integer} Image width.
• height {Integer} Image height.
• components {Integer} Image components bytes.

# imagecodec.info(buffer)

• buffer {Buffer} Image file data buffer.
• Returns: {Object} Image pixel object.

Get image size information. The internal storage of buffer is image data with format (jpg, png ...).

The returned object contains the following members:

• width {Integer} Image width.
• height {Integer} Image height.
• components {Integer} Image components bytes.