Lossless JPEG - can't find any example images, DICOM files

Question

I'm currently working on the lossless JPEG files(not JPEG-LS). It's really hard to find any files to test my application on.

Particulary I need files that contain reset interval markers, multiple DC huffman tables, multiple scenes or comment markers.

Do you know where I could find any lossless JPEG files? Do you yourself have any that you could share?

Thanks in advance, Witek.

EDIT: i could also use DICOM files using this compression standard (tag (0002,0010) Transfer syntax UID = 1.2.840.10008.1.2.4.70)

Answer 1

On the following site you can find a few DICOM lossless JPEG files, in particular with the transfer syntaxes 1.2.840.10008.1.2.4.57 and .70. Consult the Transfer Syntax section for easy identification of which data sets that provide the requested transfer syntax.

There are also a number of lossless JPEG images of different flavors on the NEMA DICOM FTP site. For more detailed information on the various data sets, please consult the README file.

Answer 2

Here's a large collection of dicom sample images: There are some JPEG lossless images among them. Some subfolders have images that are not valid DICOM, but that is usually documented. By the same maintainer there is also this list of links.

Lossless JPEG is most widely used in XA (cathlab) cine images. These are always grayscale, and exist as 8 or 10 bit images.

You could also setup a free PACS like DCM4CHEE or conquest, send it uncompressed images and have them forward the images jpeg-lossless compressed. The advantage of this is that you can create images of different color spaces, bit depths, planar/bypixel, etcetera. Color spaces are interesting: people sometimes make mistakes to transform the color space like for Jpeg lossy, which you should not do.

Most likely none of these images require advanced stuff like restart markers. If you want to check if this works, create bitstreams with the IJG implementation and package them in DICOM.

EDIT: be warned that there are buggy images out there. I am using an implementation based on the IJG code.