This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 Switzerland License.

Description of problems induced by the SIGMA Cameras SD10 and SD14 corrupting Image Data

(by Hans Loepfe, HALO Photographs, Switzerland)
Support at SIGMA Photo Japan appears to be very helpful in resolving this issue.

Corrupted X3F Image Files

It occured to me several times that the SIGMA Camera SD10 and SD14 write corrupted data onto the CF-Card.
First I thought it to be a problem of a specific CF-Card, but it turned out that I got corrupted Image Files on several of my CF-Cards in different sectors.
I always fromat the CF-Cards in the camera prior to use.
Installation of the latest firmware releases did not bring any change so far.

Therefore my assumption is that the solution to this problem is to be found in the Cameras Operating System.
Most likely and specifically in the section of the code with the procedures of writing data.

Below is sample of a corrupted X3F Image File: (created with 'XnView')
sample of corrupted X3F Image File

A detailed portion of the bottom right corner of the corrupted image:
detailed portion of corrupted X3F Image File

For your own perusal you may download the corrupted X3F-Image-File itself by clicking the URL below:
download corrupted X3F-Image-File: SDIM9221.X3F

other files Sigma Photo Pro cannot process:
download corrupted X3F-Image-File: SDIM5919.X3F
download corrupted X3F-Image-File: SDIM8121.X3F

Latest corrupted X3F-Image Data, tkane with another SIGMA SD14 (April 13th., 2008):
download corrupted X3F-Image-File: SDIM0014.X3F
download corrupted X3F-Image-File: SDIM0161.X3F
download corrupted X3F-Image-File: SDIM0162.X3F

Loading the original image in SIGMA Photo Pro (SPP) version 2 and/or 3 produces an error.
By Definition the X3F Format includes a Thumbnail-Image in JPEG Format.
Apparently SPP uses exactly this JPEG-image tp produce the image-file list as SPP does not yet produce an error.
Upon the intention to change adjustments SPP tries to access the actual image data and since this data is corrupted SPP throws an error.

When applying a saved set of settings to several X3F Image Files, the conversion process does not report any errors. The file in question simply is not being converted.
For example when shooting several images such as for a panoramic set of images to be stiched together later, the user realizes the fact of corrupted image data when it's too late. Both cameras the SD10 and the SD14 do not know if the captured image-data has been written to the CF-Card properly. Hence both Cameras cannot provide any information of an Image-Data error upon or after writing data to the CF-Card. The result is that the photographer does not know wether the shots taken are successfull stored on the CF-Card.

The panorama below reveals this as one image is simply missing. Actually it is exactly the sample image.
Panoramic Pre-View of this Sample

Click to view full Panoramic View of this Sample

So far 'XnView' is the only tool I found to extract all of the image data (including the corrupted image data). The tool 'XnView' provides an export function to various formats. This function allows to obtain the actual 'raw' unconverted image data. 'XnView' was used to produce the images above. An attempt to use Photoshop to adapt the 'salvaged' raw image in TIF Format to the surrounding Images may help to complete this sample panorama, but it is mostly impossible or at least very difficult to use Photoshop to 'recreate' the adjustments applied by SPP. Especially when the X3F-fill function and/or sharpening was applied.
I find it interesting that when the cameras internal RAM is not filled with more than one (1) image then this problem does NOT occur. In other words, when shooting in continous mode (using the cameras internal RAM for intermediate image storage, one may run the risk to end up with corrupted images.

Conclusion:

It seems as if in certain unknown situations the start byte position table for each row of the Huffman-encoded raw pixel data is misplaced.

My assumption is that the cameras Operating System has problems to concurrently write image data to the CF card and its internal data buffer.

The Camera needs a procedure to check if image data has been written to CF-Card properly. This function could inform the Photographer about possible Image data corruption. (and allow to retake that shot in time, when still on location). The complete writing process of X3F-Image data to CF-Cards shall be revised by SIGMA or FOVEON. These updates could be implemented in form of a firmware-upgrade. In addition the process of formatting of CF-Cards shall not only rebuild the FAT, the camera or maybe SPP should provide a proper formatting function that includes the exclusion of possible bad sectors on CF-Cards.

Credits:

Support at SIGMA Japan provides great service, Mr. Vuslat Tatar is very helpful.

XnView by Pierre-Emmanuel Gougelet, Reims, France
Web site: www.xnview.com

Drop'n Decode X3F: a Sigma SD10/14 compatible FOVb (.X3F) file decoder
by yos@tokyo
Web site: http://yos.the-ninja.jp/

Update:

January, 9th. 2008: SIGMA Photo, Japan, is investigating the issue of corrupted image data.

February, 10th. 2008: SIGMA Photo, Japan, has strongly advised to install the latest Firmware (v1.05).
Currently it seems as the problems described above are resolved with this firmware update.

April, 13th. 2008: After several shootings of panoramas the problem described above remains unresolved.
OTT + Wyss AG (Distributor of SIGMA PRoducts in Switzerland) will send my SIGMA SD14 to SIGMA Photo, Japan for further investigation
The above issue has NOT been tested with Firmware v1.07.

Contact:

In case you would like to contact me please use this Contact form: Contact & Anfragen

HALO-Photographs