JPG's vs BMP's

montage wrote on 8/30/2002, 10:41 PM

When I scan my photo's in I have always saved them as BMP files.
I am considering changing to JPG's, hoping it will speed up the rendering process by not making VF juggle 100+ 6MB Bitmaps.
Presently it takes 14 Hours for me to render a 15Min Video.
Is this going to change the quality of my finished project if VF is rendering from JPG's instead of BMP's?

Comments

randy-stewart wrote on 8/30/2002, 11:49 PM

Montage,
No, the quality change shouldn't be noticeable. JPEG files are much, much smaller and should signficantly cut down your render time. I've used them exclusively for all my videos and have had super results.
Randy

montage wrote on 8/31/2002, 4:42 PM

Thanks Randy.
You've saved me from spending a weekend finding the answer by trial and error.

Chienworks wrote on 8/31/2002, 9:27 PM

montage: 6MB? Are these images 1600x1200? If so, are you zooming in and cropping at all? If not, and if you're using them as straight full-frame images, there's no need to have them any larger than 655x480 (or 720x576 in PAL land). Any larger than that is a waste, takes much longer to render, and in fact gives a fuzzier image than using the project frame size.

montage wrote on 9/1/2002, 10:37 PM

In all honesty, I am learning this as I go along. However, My usual way of doing things is preview the scanned image, crop it, and scan it in as a bitmap. I went through some of my current files and the average bitmap file is between 4.5 to 6MB. (Some 8x10's I scanned are 20MB.) I kinda feel silly now, but, I plead ignorance.
I went under the (wrong) assumption that the larger the file, the better the final product will be. I'm a little fuzzy about what I need for DPI and the Frame size. What units is 655 x 480 -MM, Inches, DPI? Usually I just scanned things in and drawn the little box arount the picture and said "SAVE". If these things will cut down rendering time, I'm all for that. Right now I start the rendering before I go to bed and hope the computer doesn't crash before it get's done the next day around noon.

Chienworks wrote on 9/1/2002, 11:54 PM

There is no such thing as DPI in video ;) so don't bother trying to worry about it too much.

If you're scanning a 4x6" photo and want it to be about 655x480, you can scan it at 150dpi and get a 900x600 image. This isn't too much bigger than the ideal size, and it gives you a little bit of play for cropping. Generally i'll crop and resize the photos to the exact size i want in the photo editing software i use after scanning rather than trying to get the original scan perfect. Using images this size can probably cut your rendering time in half or better as compared to using 1600x1200 images.

As far as the quality thing goes, the more VideoFactory has to shrink an image while rendering it, the more it will fuzz neighboring pixels together resulting in a softer image.

montage wrote on 9/2/2002, 7:25 PM

Thanks to Both of you, This forum has taught me more than I ever would have guessed.