[][src]Module opencv::imgcodecs

Modules

prelude

Enums

ImreadModes

Imread flags

ImwriteEXRTypeFlags
ImwriteFlags

Imwrite flags

ImwritePAMFlags

Imwrite PAM specific tupletype flags used to define the 'TUPETYPE' field of a PAM file.

ImwritePNGFlags

Imwrite PNG specific flags used to tune the compression algorithm. These flags will be modify the way of PNG image compression and will be passed to the underlying zlib processing stage.

Constants

IMREAD_ANYCOLOR

If set, the image is read in any possible color format.

IMREAD_ANYDEPTH

If set, return 16-bit/32-bit image when the input has the corresponding depth, otherwise convert it to 8-bit.

IMREAD_COLOR

If set, always convert image to the 3 channel BGR color image.

IMREAD_GRAYSCALE

If set, always convert image to the single channel grayscale image (codec internal conversion).

IMREAD_IGNORE_ORIENTATION

If set, do not rotate the image according to EXIF's orientation flag.

IMREAD_LOAD_GDAL

If set, use the gdal driver for loading the image.

IMREAD_REDUCED_COLOR_2

If set, always convert image to the 3 channel BGR color image and the image size reduced 1/2.

IMREAD_REDUCED_COLOR_4

If set, always convert image to the 3 channel BGR color image and the image size reduced 1/4.

IMREAD_REDUCED_COLOR_8

If set, always convert image to the 3 channel BGR color image and the image size reduced 1/8.

IMREAD_REDUCED_GRAYSCALE_2

If set, always convert image to the single channel grayscale image and the image size reduced 1/2.

IMREAD_REDUCED_GRAYSCALE_4

If set, always convert image to the single channel grayscale image and the image size reduced 1/4.

IMREAD_REDUCED_GRAYSCALE_8

If set, always convert image to the single channel grayscale image and the image size reduced 1/8.

IMREAD_UNCHANGED

If set, return the loaded image as is (with alpha channel, otherwise it gets cropped).

IMWRITE_EXR_TYPE

override EXR storage type (FLOAT (FP32) is default)

IMWRITE_EXR_TYPE_FLOAT

store as FP32 (default)

IMWRITE_EXR_TYPE_HALF

store as HALF (FP16)

IMWRITE_JPEG2000_COMPRESSION_X1000

For JPEG2000, use to specify the target compression rate (multiplied by 1000). The value can be from 0 to 1000. Default is 1000.

IMWRITE_JPEG_CHROMA_QUALITY

Separate chroma quality level, 0 - 100, default is 0 - don't use.

IMWRITE_JPEG_LUMA_QUALITY

Separate luma quality level, 0 - 100, default is 0 - don't use.

IMWRITE_JPEG_OPTIMIZE

Enable JPEG features, 0 or 1, default is False.

IMWRITE_JPEG_PROGRESSIVE

Enable JPEG features, 0 or 1, default is False.

IMWRITE_JPEG_QUALITY

For JPEG, it can be a quality from 0 to 100 (the higher is the better). Default value is 95.

IMWRITE_JPEG_RST_INTERVAL

JPEG restart interval, 0 - 65535, default is 0 - no restart.

IMWRITE_PAM_FORMAT_BLACKANDWHITE
IMWRITE_PAM_FORMAT_GRAYSCALE
IMWRITE_PAM_FORMAT_GRAYSCALE_ALPHA
IMWRITE_PAM_FORMAT_NULL
IMWRITE_PAM_FORMAT_RGB
IMWRITE_PAM_FORMAT_RGB_ALPHA
IMWRITE_PAM_TUPLETYPE

For PAM, sets the TUPLETYPE field to the corresponding string value that is defined for the format

IMWRITE_PNG_BILEVEL

Binary level PNG, 0 or 1, default is 0.

IMWRITE_PNG_COMPRESSION

For PNG, it can be the compression level from 0 to 9. A higher value means a smaller size and longer compression time. If specified, strategy is changed to IMWRITE_PNG_STRATEGY_DEFAULT (Z_DEFAULT_STRATEGY). Default value is 1 (best speed setting).

IMWRITE_PNG_STRATEGY

One of cv::ImwritePNGFlags, default is IMWRITE_PNG_STRATEGY_RLE.

IMWRITE_PNG_STRATEGY_DEFAULT

Use this value for normal data.

IMWRITE_PNG_STRATEGY_FILTERED

Use this value for data produced by a filter (or predictor).Filtered data consists mostly of small values with a somewhat random distribution. In this case, the compression algorithm is tuned to compress them better.

IMWRITE_PNG_STRATEGY_FIXED

Using this value prevents the use of dynamic Huffman codes, allowing for a simpler decoder for special applications.

IMWRITE_PNG_STRATEGY_HUFFMAN_ONLY

Use this value to force Huffman encoding only (no string match).

IMWRITE_PNG_STRATEGY_RLE

Use this value to limit match distances to one (run-length encoding).

IMWRITE_PXM_BINARY

For PPM, PGM, or PBM, it can be a binary format flag, 0 or 1. Default value is 1.

IMWRITE_TIFF_COMPRESSION

For TIFF, use to specify the image compression scheme. See libtiff for integer constants corresponding to compression formats. Note, for images whose depth is CV_32F, only libtiff's SGILOG compression scheme is used. For other supported depths, the compression scheme can be specified by this flag; LZW compression is the default.

IMWRITE_TIFF_RESUNIT

For TIFF, use to specify which DPI resolution unit to set; see libtiff documentation for valid values

IMWRITE_TIFF_XDPI

For TIFF, use to specify the X direction DPI

IMWRITE_TIFF_YDPI

For TIFF, use to specify the Y direction DPI

IMWRITE_WEBP_QUALITY

For WEBP, it can be a quality from 1 to 100 (the higher is the better). By default (without any parameter) and for quality above 100 the lossless compression is used.

Functions

have_image_reader

Returns true if the specified image can be decoded by OpenCV

have_image_writer

Returns true if an image with the specified filename can be encoded by OpenCV

imdecode

Reads an image from a buffer in memory.

imdecode_to

Reads an image from a buffer in memory.

imencode

Encodes an image into a memory buffer.

imread

Loads an image from a file.

imreadmulti

Loads a multi-page image from a file.

imwrite

Saves an image to a specified file.