Black edges on images?

[ROCKYSUMMIT]

Wondering why I sometimes get black edges on images when I transfer them from a card reader onto my Mac computer. Looks like a cropping or image size ratio type of thing. It doesn't seem to effect the image quality or present any problems, and doesn't happen very often either. Just don't know if it's an occasional card reader problem or what. Thanks in advance for any ideas.

 

[DougPaul]

I'd be more inclined to guess that it is a camera problem or a problem with your viewing software. The reader should simply enable you to copy data files from the data card to your computer hard drive. If the file is altered by the reader, then the image is likely to show much more damage than a black border.

Viewer bug:
If you can transfer the picture file to another computer, try viewing it there. (Or post it on a webserver and ask someone else to view it for you.) Or try a different picture viewer (web browsers can view JPEG files directly--just use the file path name for the URL).

File transfer bug:
If you have an alternate way of transferring the data (eg many cameras have a direct USB interface), try it and compare it to the data transferred via the card reader. Or have someone else read the card and compare the results. (If you need to compare files across computers, compute an MD5 checksum on both and manually compare the checksums. Viewing the file on two different computers uses two different viewers and does not isolate a file transfer bug.)

If it isn't a viewer or file transfer bug, then it is most likely a camera problem.

Doug

 

[WinterWarlock]

Tony - I remember an old camera of mine that occasionally tried to digitize the horizontal register on the CCD...gave me a funky looking black edge. Can't even remember what/when it happened, just that it did. Is the edge pure black (close to zero grey value) or splotchy?

 

[ROCKYSUMMIT]

Scott, it's a hard edge and definitely black. Doug, it sounds like you're right. I called Canon and they said since I don't see it in the LCD, that it isn't a problem with the camera and it sounds like I need an I-Photo update. Hopefully that is it. I'll check it out when I get home. Thanks guys!
-Tony

 

[DougPaul]

Scott, it's a hard edge and definitely black. Doug, it sounds like you're right. I called Canon and they said since I don't see it in the LCD, that it isn't a problem with the camera and it sounds like I need an I-Photo update. Hopefully that is it. I'll check it out when I get home.

Just because it isn't visible in the LCD doesn't mean that it isn't in the JPEG. If the black region is narrow, it simply might be too small to show on the LCD. JPEGs can store a thumbnail image in the EXIF data within the JPEG. The LCD might be showing a good thumbnail in a JPEG containing a bad image.

In any case it is relatively easy to determine where the fault lies. If an independent viewer shows the same bad image, the camera is most likely at fault. If the independent viewer shows a good image, then your old image viewing software is most likely at fault.

Doug