PCD to PPM converter

.pcd

Kodak – the photography giant needed a way of effectively archiving images on different data storage media, the solution they came up with is the Photo CD format. Taking pictures with cameras with sophisticated lenses and documents scanned with high definition scan heads always generates high-resolution copies that could eat up chunks of memory space on Kodak devices. Forthwith, the PCD format utilizes an image compression system to encode images in slices of 24-bit. A PCD file can support images of multiple resolutions, with the highest being 6144×4096 pixels.

Though PCD format supports image resolutions as high as 6144×4096 pixels, images are mostly encoded unto storage media at a resolution of 3072×2048 pixels. However, these two image resolutions are encoded with a similar color depth of 24-bit. Saving images in the PCD format is quite similar to the proprietary high-resolution video compression technology patented by Apple Inc.

Kodak

.ppm

Portable pixmap images can be stored using the PPM format, which is basic, for example, color (PPM), grayscale (PGM), and black and white (PBM). A portable pixmap can provide a hallway representation of information in the conversion process of bitmap image files of the three types mentioned between different platforms. Jeff Poskanzerom developed the PPM format.

PPM files comprise sequences of a single or more PPM image. Data, padding, and limits do not exist before or after or in the middle of images. Every PPM comprises a single magic number used in identifying the type of file; the magic number for a PPM image is the two-character P6, whitespace (blanks, TABs, CRs, and LFs), and width presented as ASCII characters in decimal. It also comprises whitespace again, which is shown in ASCII decimal. Whitespace, the color value at a maximum (Maxval), is in decimal form, and it should be greater than zero but less than 65536. It is also composed of another single whitespace character, which is on another line. Lastly, it is composed of a raster of height rows found in reverse chronological order. The rows are comprised of width pixels in a left to right format. The samples represented have a pure binary nature, which is by one or two bytes. I byte has a Maxval of less than 256; otherwise, it is 2 bytes. The first byte is the most relevant. The straightforward format is another version of the PPM that exists but is most uncommon.

Jef Poskanzer