File Formats: JPEG and LEAD Compressed (JPG, J2K, JP2, JPM, JLS, CMP, and CMW)

LEADTOOLS reads and writes the following LEAD and JPEG compressed formats:

Both JPEG 4:4:4 and Lossless JPEG will be recognized when getting file information.

NOTE: JFIF  4:1:1 and 4:2:2 formats use subsampling for the color components. In the case of 411, the color components for 4 pixels are averaged during compression. This will cause a color shift, but the shift is tolerable for low compression ratios. If you have high compression and repeated savings, then the color shift will increase.  Due to inherent limitations of the JPEG algorithm, the only ways to avoid this are: (a) avoid repeated load and resave, or (b) use 4:4:4  format, which has no subsampling.

Both TIFF JPEG 4:4:4 and Lossless JPEG will be recognized when getting file information.

For general information, refer to Compression Using LEAD and JPEG Formats. For instructions for implementing progressive formats, refer to Controlling Progressive Loads and Saves. JPEG and LEAD files can contain many comment fields of various types. You can use the L_ReadFileComment  function to read comments in an existing file. Before writing a file, you can use the L_SetComment function to create an array of comments to be saved in the file. You can use the L_DeleteComment function to delete a comment field from a file.

Please note that LTCLR is required for loading JPEG CMYK images and for loading and saving JPEG LAB images.

File constants associated with this file format are as follows:

Constant

Read Support

Write Support

Description

FILE_CMP

8 BPP (grayscale)
24 BPP

8 BPP (grayscale)
24 BPP

[5] LEAD CMP compressed format.

FILE_JPEG

8, 12, 16 BPP (grayscale)
24 BPP

8, 12, 16 BPP (grayscale)
24 BPP

[10] JPEG File Interchange Format.

FILE_JPEG_411

8 BPP (grayscale)
24 BPP

8 BPP (grayscale)
24 BPP

[21] JPEG File Interchange Format, 4:1:1.

FILE_JPEG_422

8 BPP (grayscale)
24 BPP

8 BPP (grayscale)
24 BPP

[21] JPEG File Interchange Format, 4:2:2.

FILE_JPEG_CMYK 24 BPP 24 BPP [391] JPEG File Interchange Format, CMYK 4:4:4.
FILE_JPEG_CMYK_411 24 BPP 24 BPP [392] JPEG File Interchange Format, CMYK 4:1:1.
FILE_JPEG_CMYK_422 24 BPP 24 BPP [393] JPEG File Interchange Format, CMYK 4:2:2.

FILE_JPEG_LAB

24 BPP

24 BPP

[171] JPEG File Interchange Format, CieLAB 4:4:4.

FILE_JPEG_LAB_411

24 BPP

24 BPP

[172] JPEG File Interchange Format, CieLAB 4:1:1.

FILE_JPEG_LAB_422

24 BPP

24 BPP

[173] JPEG File Interchange Format, CieLAB 4:2:2.

FILE_JPEG_RGB

24 BPP

24 BPP

[182] JPEG File Interchange Format, RGB 4:4:4.

FILE_JP2

8, 12, 16 BPP (grayscale)
24, 32, 48, 64 BPP (color)

8, 12, 16 BPP (grayscale)
24, 32, 48, 64 BPP (color)

[163] JPEG 2000 File.

FILE_J2K

8, 12, 16 BPP (grayscale)
24, 32, 48, 64 BPP (color)

8, 12, 16 BPP (grayscale)
24, 32, 48, 64 BPP (color)

[164] JPEG 2000 Stream.

FILE_JPM

8,24 BPP

None

[347] JPEG 2000 (Part 6) JPM.

FILE_JLS

8, 12,16 BPP (grayscale)

24 BBP (color)

8,12, 16 BPP(grayscale)

24 BBP (color)

[356] JPEG-LS Lossless and Near Lossless.

FILE_JLS_LINE

24 BBP (color)

24 BBP (color)

[367] JPEG-LS Lossless and Near Lossless  (Line-interleaved.)

FILE_JLS_SAMPLE

24 BBP (color)

24 BBP (color)

[368] JPEG-LS Lossless and Near Lossless.

(Sample-interleaved)

FILE_JPX

8, 12, 16 BPP (grayscale)

24, 32, 48, 64  BPP (color)

8, 12, 16 BPP (grayscale)

24, 32, 48, 64  BPP (color)

[323] JPEG 2000 Extension (Part 2).

FILE_CMW

8, 12, 16 BPP (grayscale)
24 BPP

8, 12, 16 BPP (grayscale)
24 BPP

[165] LEAD Wavelet CMP compressed format.

Required DLL: For a listing of the exact DLLs needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Related Formats: JPX - JPX Format, EXIF - Exif Formats, FPX - Kodak Format, TIFF / BigTIFF - Tagged Image File Format.

Platforms

Win32, x64, Linux.

Help Version 19.0.2017.10.19
Products | Support | Contact Us | Copyright Notices
© 1991-2017 LEAD Technologies, Inc. All Rights Reserved.
LEADTOOLS Raster Imaging C API Help