ImageIO Class Reference

Implementation of file input/output operations for images. More...

#include <easy3d/fileio/image_io.h>

Static Public Member Functions
static bool	load (const std::string &file_name, std::vector< unsigned char > &data, int &width, int &height, int &channels, int requested_channels=0, bool flip_vertically=true)
	Load image data from a file.
static bool	save (const std::string &file_name, const std::vector< unsigned char > &data, int width, int height, int channels, bool flip_vertically=false)
	Write image data into a file.

Detailed Description

Implementation of file input/output operations for images.

Member Function Documentation

load()

bool load ( const std::string & file_name, std::vector< unsigned char > & data, int & width, int & height, int & channels, int requested_channels = 0, bool flip_vertically = true )

static

Load image data from a file.

The following formats are supported: JPG/JPEG, PNG, BMP, PSD, TGA, GIF, HDR, PNM (.ppm and .pgm). The file format is determined by the file extension given in the file name.

Parameters

file_name	The image file to load.
data	Outputs the image data. Data will be empty if the specified image file doesn't exist, allocation failed, or the image is corrupt or invalid. The image data returned is a 1D array of 'unsigned char' which points to the pixel data, or empty when failed. The pixel data consists of 'height' scanlines of 'width' pixels, with each pixel consisting of N interleaved 8-bit channels/components; the first pixel points to the top-left-most in the image. There is no padding between image scanlines or between pixels, regardless of format. The number of channels N is 'requested_channels' if it is non-zero, or 'channels' otherwise. An output image with N channels has the following components interleaved in this order in each pixel: N (Channels) Components 1 Grey 2 Grey, Alpha 3 Red, Green, Blue 4 Red, Green, Blue, Alpha
width	Outputs image width in pixels. Unchanged if failed.
height	Outputs image height in pixels. Unchanged if failed.
channels	Outputs the number of 8-bit image channels per pixel. Unchanged if failed.
requested_channels	User requested image channels. If non-zero, force to treat the image as if it has this number of components. For example, if you set it 4, you will always get RGBA output, but you can check channels to get the actual number of channels.
flip_vertically	Flip the image data vertically if it is true (default value). This is convenient for OpenGL applications where the first pixel in the output array is expected to be the bottom left corner of the image.

Returns

true on success or false if failed. Example usage:

int width, height, channels;
std::vector<unsigned char> data;
bool success = ImageIO::load(data, file_name, &width, &height, &channels, 0);
// ... process data if true returned ...

save()

bool save ( const std::string & file_name, const std::vector< unsigned char > & data, int width, int height, int channels, bool flip_vertically = false )

static

Write image data into a file.

The following formats are supported JPG/JPEG, PNG, BMP, and TGA. The file format is determined by the file extension given in the file name.

Parameters

file_name	The file to which the image data will be saved.
data	The image data. The image data storage must follow: N (Channels) Components 1 Grey 2 Grey, Alpha 3 Red, Green, Blue 4 Red, Green, Blue, Alpha
width	The width of the image, in pixels.
height	The height of the image, in pixels.
channels	The number of 8-bit image channels per pixel.
flip_vertically	Flip the image data vertically before writing.

Returns

Return true on success or false if failed.

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The documentation for this class was generated from the following files:

• G:/3_code/Easy3D/easy3d/fileio/image_io.h
• G:/3_code/Easy3D/easy3d/fileio/image_io.cpp