Read JPEG image from file (in dipIO)
#include "dipio_jpeg.h"
dip_Error dipio_ImageReadJPEG ( image, filename, imageNumber, photometric )
This function reads an image from the JPEG file and puts it in image. image must be allocated before calling this function. photometric is set to either DIPIO_PHM_RGB or DIPIO_PHM_GREYVALUE. If photometric is 0, the image will be read in as grey-value, even if color information is present in the file. Color images are allocated as 3D images, with the different samples along the 3rd. dimension.
| Data type | Name | Description |
| dip_Image | image | Output image |
| dip_String | filename | File name |
| dipio_PhotometricInterpretation * | photometric | Photometric interpretation |
The enumerator dipio_PhotometricInterpretation contains the following constants:
| Name | Description |
| DIPIO_PHM_GREYVALUE | No colour information present; it's a grey-value image. |
| DIPIO_PHM_RGB | RGB image (the first three planes are red, green and blue) |
| DIPIO_PHM_RGB_NONLINEAR | Non-linear R'G'B' image (RGB channels to the power of 0.4) |
| DIPIO_PHM_CMY | CMY image (the first three planes are cyan, magenta and yellow) |
| DIPIO_PHM_CMYK | CMYK image (the first four planes are cyan, magenta, yellow and black) |
| DIPIO_PHM_CIELUV | CIE L*u'v' image (the first three planes are luminosity, u* and v*) |
| DIPIO_PHM_CIELAB | CIE L*a*b* image (the first three planes are luminosity, a* and b*) |
| DIPIO_PHM_CIEXYZ | CIE XYZ (the first three planes are X, Y and Z) |
| DIPIO_PHM_CIEYXY | CIE Yxy (the first three planes are Y, x and y) |
| DIPIO_PHM_HCV | HCV image (the first three planes are hue, chroma and value) |
| DIPIO_PHM_HSV | HSV image (the first three planes are hue, saturation and value) |
| DIPIO_PHM_DEFAULT | Same as DIPIO_PHM_GREYVALUE |
| DIPIO_PHM_GENERIC | Anything can be coded in the channels; the same as DIPIO_PHM_CMYK |
Most file formats support only some of these.
This function uses libjpeg (version 6b or later). Copyright (c)1994-1998, Thomas G. Lane.
ImageRead, ImageReadColour, ImageWriteJPEG, ImageIsJPEG, ImageReadJPEGInfo, Colour2Gray