I am working on a project, and would like to have fairly crisp image files in my CAD files.
Is there a specific type of image file that is better than another? I have used image files a little before, but I am hoping to create a better looking product. I am using image files from our local gis website, so I am not sure what type of image files they have on their site.
Any advice is greatly appreciated.
Edit: I saved the image file by right clicking and it saved as a JPG file.
Jimmy,
Whish I could say that one image type was better than another, but that's not really the case - at least from my perspective. Can't speak for all cad programs, but AutoCAD will import more image types than you can shake a stick at! I usually utilize .sid or .tiff (geo-tiff) files... not because one is better than the other, but because these are typical file types for aerials (at least where I download them from).
What really matters is the resolution of the image. Some imagery will have metadata associated with it that will explain the resolution. I use a lot of 1 meter resolution aerial imagery (1 pixel = 1 meter) available from my state GIS (NAIP)... It's a little fuzzy for some apllications, but works for discussion and planning purposes. Usually, the smaller the pixel size the better. Of course, this is all dependant on how the image was created, i.e. flying height, camera quality,etc. Several years ago, the EPA did low altitude flights in my area and produced some 1/2 meter (or less) resolution imagery thst is very crisp at small scale... Good stuff!
Hope this helps.
Byron is exactly right about the imagery resolution. The image file will have an associated world file that contains the metadata. If the image file is a jpg, the associated world file will be a jgw; if it is a tif, the world file will be a tfw. In Carlson, there is a command to import a image by world file that places the image where it belongs as long as you have your drawing set up in the same coordinate system as the image.
you can also play with the contrast in the properties window
it does help some aerials that become muddy with shadows
Spledeus is right, adjustment of settings can help the final appearance greatly. Something to also bear in mind is that unlike the vector based CAD image on the screen, the appearance of photo images can vary from sreen to screen and when printed out. It's worth doing test prints to get a feel for the best settings.
It's also worth making a copy image and playing around with it in a photo edit program which gives a lot more edit options than the properties dialog in ACAD.
Sometimes a 'faded' monochrome background is easier on the eye than full on color, especially if there's a lot of clutter in the image.
Thanks for all the advice. I have printed this out, and saved it for future reference.
