Last modified: 2012-04-04 00:36:49 UTC
Several of the images in the following commons cat have black streaks across portions of the thumbs. http://commons.wikimedia.org/wiki/Category:Solar_Dynamics_Observatory Sample thumbs include: https://upload.wikimedia.org/wikipedia/commons/thumb/c/cc/417176main_SDO_Guide_CMR_Page_12_Image_0002.jpg/120px-417176main_SDO_Guide_CMR_Page_12_Image_0002.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/e/ef/417176main_SDO_Guide_CMR_Page_13_Image_0003.jpg/56px-417176main_SDO_Guide_CMR_Page_13_Image_0003.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/f/fd/417176main_SDO_Guide_CMR_Page_27_Image_0002.jpg/120px-417176main_SDO_Guide_CMR_Page_27_Image_0002.jpg I've archived a the category at: http://www.webcitation.org/66exsAOAx This may be related to this bug: https://bugzilla.wikimedia.org/show_bug.cgi?id=24854
For the first image listed: bawolff@Bawolff-L:~$ exiftool 417176main_SDO_Guide_CMR_Page_12_Image_0002.jpg ExifTool Version Number : 7.30 File Name : 417176main_SDO_Guide_CMR_Page_12_Image_0002.jpg Directory : . File Size : 175 kB File Modification Date/Time : 2010:02:12 22:50:40 File Type : JPEG MIME Type : image/jpeg JFIF Version : 1.1 Resolution Unit : inches X Resolution : 150 Y Resolution : 150 DCT Encode Version : 100 APP14 Flags 0 : Encoded with Blend=1 downsampling APP14 Flags 1 : (none) Color Transform : YCCK Image Width : 579 Image Height : 579 Encoding Process : Baseline DCT, Huffman coding Bits Per Sample : 8 Color Components : 4 Image Size : 579x579 The line of interest is: >Color Transform : YCCK So apparently its using a non-standard colour transform. Googling YCCK says: "YCCK model is specific for the JPEG image compression. It is a variant of the YCbCr model containing an additional K channel (black). The fact is that JPEG codec performs more effectively if the luminance and color information are decoupled. Therefore, a CMYK image should be converted to YCCK before JPEG compression." Hence this appears basically the same issue as bug 24854 (Non-standard colour models don't work well). Duping to that bug *** This bug has been marked as a duplicate of bug 24854 ***
