JPEG images are a good data format for photographs because they contain data that is compressed in a manner optimized for the human eye. However, it is a "lossy" compression, meaning that if they are unencoded and re-encoded several times, the image will lose quality.

Sometimes all I want to do is crop a picture, to chop off uninteresting areas of the photo. Several tools can do this by working on the native JPEG data, meaning there is no loss of information from re-encoding the image.

Reviews of digital cameras can be found at dpreview.com.

My favorite part is the excellent side-by-side comparisons of any camera models.

Like many people, I have growing number of pictures from my digital camera. I decided that I wanted a digital picture frame to display them in the houseThe purchase price is just too expensive for me to afford (anywhere from US$100 to $900 or more) so instead I am building one.

I acquired an older HP Omnibook 2000 laptop. It has a 2GB hard drive, PCMCIA slots, and an 800x600 TFT LCD display. I am now working on the software setup. After that is working then I will do the hardware frame part.

Duo 2000

The Concord Duo 2000 camera has a 2 megapixel sensor, USB interface, 7 MB internal memory, and supports an additional MMC memory card. It can take pictures at 1600x1200, 1280x960, or 640x480 resolution.

There are two ways to get pictures out of this camera with Linux. You can talk to it directly through its USB interface as a USB storage device, or read the MMC card with a separate card reader.

With digital cameras so popular, the USB multi-format card readers are readily available, inexpensive, and supported on Linux.

Digital Photography Pocket Guide

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The Toshiba PDR-M11 camera has a 1.3 megapixel sensor, USB interface, and uses a SmartMedia memory card. It can take pictures at 1280x960 resolution or 640x480 resolution.

There are two ways to get pictures out of this camera with Linux. You can talk to it directly through its USB interface using GPhoto 2 or read the SmartMedia card with a separate card reader.

I had mixed results with GPhoto. The PDR-M11 uses a proprietary protocol on the USB connection. It does not use either the USB mass-storage interface, nor the newer standard PTP digital camera protocol. I was able to use both gtkam and the command-line gphoto tool to list pictures on the camera, and retrieve them one at a time. However, attempting to retrieve more than one picture at a time aborted with an unknown error. And more than once it locked up the machine hard in Fedora Core 1, presumably from a USB kernel driver problem. This is highly unusual in my Linux experience and not acceptable.

Reading the SmartMedia card with a separate card reader worked fine. Needless to say, I'm sticking with that method.

The particular one I got (used on EBay) has a problem with blocky pixelation at 1280 resolution, which does not happen at 640 resolution. Strange artifact lines appear along contrasting areas such as edges or borders of objects. You can see a 1280 problem picture and 640 clean picture taken of the same scene, to compare. This happens regardless of whether the picture is taken in JPEG or TIFF mode, and regardless of whether it is downloaded through GPhoto or read directly from the SmartMedia card. The problem is quite obvious looking at most pictures, so I am therefore assuming it is not a design flaw with the M11 but rather that my particular camera is broken somehow.

It still works fine in 640x480 mode, and produces better 640x480 pictures than the Polaroid Fun Flash 640.

• Camera specifications
• Owner's Manual

Shooting Digital

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This camera has 640x480 resolution with built-in memory and a serial interface, holding about 16 pictures. There is no USB nor memory card slot.

This camera was designed as Windows-only, with proprietary TWAIN drivers to talk to the camera over the serial port.

Work was done to reverse-engineer the serial protocol for GPhoto 2. It works, and I was able to get pictures from the camera as PPM files using gtkam and the gphoto command-line tool.

In my testing, the colors are slightly different in the gphoto output, compared to the Windows Twain driver output.

The Fun! Flash 640 is different from the PDC-640 and 640SE models. Web references for the Fun Flash 640 are hard to find in 2005. Most searches turn up information about the PDC model. I recommend GPhoto as the main resource for technical details.