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Guest Hugo

Seeking advice into bying a digital camera.

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I'm looking after to get one for my casual needs. But I foresee using it to capture building and whatnot photo-textures for scenery creation. I'm presently leaning toward Sony's DSCP32, 3.2 MB. It handles picture sizes from 640x480 to 2048x1536 pixels.For sceneries, I would normaly work with 512x512 texture files. Now, as far as I know, using Paintshop Pro 6, when I try to reduce a 2048x1536 picture (taken on the web) to a 512 pixel width, the resulting picture is degraded in such a way that it wouldn't be worth to use it as a texture.My questions.Is there a way, I am not aware of, to get a reduced picture size by a fair amount, as mentionned above, that would still keep an acceptable quality for scenery texture usage? With PS Pro? Or with any other graphic programs like Photoshop or others?OrWould it be better to use the camera's lower setting, 640x480, and frame the picture on the spot, so it would require none or very little size reduction when transfered into a final 512x512 texture file?Thanks for any advice,Hugo

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In my experience, you will get a better image if you shoot in a higher resolution (that is, higher rather than highest) and resize it.I always use Picture Publisher for textures, but I'm sure that there are a lot of good tools around. The secret is to find one which can handle resampling well. Picture Publisher offers a choice of resampling (they call it interpolation)Bi-linear, Average, Bi-cubic and SplineEach has its strengths, so you really need to test each method. I use Bi-cubic, as it gives the best result for me. I do need to run an unsharp mask though as the reduction does blur the image.You really need to check to see what options you have with PSP.Another method which works if your software doesn't have great resampling is to reduce the image in steps. Reduce to 80%, sharpen, reduce again etc until you get where you want to be.

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Yes, it is definitely worth taking the pics at a higher resolution. This also makes it possible to take the pic in such a way that you can select a zoom setting with as little lens distortion as possible, and then crop the picture to your needs. There are many good cameras around, and the amount of money you are willing to spend on it will decide what options you have. Personally I am a Canon fan, I have a Canon PowerShot G3. Have been using a Canon PowerShot S45 too, and i really like the optical features and the software in the PowerShot cameras... Additionally, you will need a good graphics software, Photoshop, PaintShop Pro or equivalent. Personally I am using PaintShop Pro 8, and I am very satisfied with it's features. When making textures some important features are - correction of straightness and perspective- correction of lens distortion- good resizing resampling features (using various methods mentioned by toprob)- unsharp maskAnd of course all basic functions as white balance, brightness, contrast etc. There is one freeware graphics program called GIMP that has been recommended by some - I have no personal experience of it though...A tip: When making textures it is good to initially work with larger pics (1024x1024 or even bigger) and then in the final phase resize it to 512x512 or 256x256....Bamcehttp://personnel.scribona.fi/fly!/msfs/signature_bof.gif

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Thanks Toprob and Bamce for your reply. Well I tryed Toprob suggestion to resize by 80%, sharpen, resise again, sharpen etc. to finaly bring the image down from 2048x1536 to 512x384 using Bi-cubic resample.The initial image was taken here: steves-digicams.com/2003_reviews/sony_p32/samples/DSC01100.JPG(add http://.www before the address up here. If I do, the very large image shows in this post and I do not think this would be appropriate...)The first image attached below is the result of the above process.The second one is a single pass resizing straith from 2048 to 512 width again using bi-cubic....Hum! Dosen't seam those 2 52 kb files can be attached to this post. I wil try to attach them to a second one... Although the step procedure seams to yield a better result, I don't think any of the 2 (or part of) would be suitable for texture usage.Is it possible for you to get the original image work it and post it here so I could compare and find what I could expect from a proper resizing process.Thanks for your help guys,Hugo

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That picture has several problems, and it needs a lot of work with the graphics software to make it at least somewhat suitable for a partial texture of that house. The biggest problem is the bright sunshine which gives heavy shadows and bright highlights....Generally you need pictures taken as well as possible from a 90 degree angle towards each wall of the building, preferrably with light overcast sky conditions (no direct sunshine, but enough light to give slight shadows) to make really good textures. Avoid perspective and lens distortions!But let's give it a theoretical try: I would cut out only the area containing the house from that pic. Then I would cut it into three pieces by selecting the leftmost part of the building (tried it - you can do a direct 512x512 of that part), the central part of the building with the pointed roof (some 650X650 pixels and finally the right part of the building (can not be used for textures - you will need another shot from that direction). Then you will have to correct for perspective (not very much, though), resize the bigger picture to 512x512. Then remove redundant stuff from the pic (flagpoles, palms and bushes etc.) so that you are left with plain walls. Then correct for shadows/highlights (very difficult with this pic!). In the end you would be left with two 512x512 textures for a part of your building. Very little resizing needed. Make separate textures for details requiring good readability, like the blue sign etc....Finally I would resize both (+ additional textures from other pics) to 256x256 to save fps.Bamcehttp://personnel.scribona.fi/fly!/msfs/signature_bof.gif

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Just as an explanation to my text above... Here are two pics. The first one is the workin area in red and the two useful parts of the pic in yellow frames (approximately):http://fs-files.myownsite.org/Image1.jpgThe second one shows the central part of the building, slightly reworked and a perspective-corrected version of the balcony added to the lower part of the texture:http://fs-files.myownsite.org/Image2.jpgNote, this is a very fast test, not a quality job.. :-)Bamcehttp://personnel.scribona.fi/fly!/msfs/signature_bof.gif

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Gday all, one important point thats been missed with regards to a digital cam is not so much the Mega pixels it captures but the distance you are takeing your shot from and the type of zoom. The only zoom to go for is Optical and Not Digital, Optical is where you are moving your focal point closer to the subject prior to capturing the image and is a true zoom, Digital zoom is the image captured, resampled and then expanded and therefore will suffer interpolation, Allso, the higher the zoom you use, the more the image will be perceptable to camera shake unless you use a good tripod or have a steady hand.3 megapixel is more than adequate and very good results can be obtained with a 2 megapixel cam ! the secret of the texture is how you use the photo as a base file for creating a texture . i have used upto 7 diff images compiled into one final image and then save to DXT format.The only benefit of a larger megapixel cam is that you can crop a section of the image down to the area you want to use with minimum loss of quality from the base file. Another method is to stand closer to the subject area you want to photo and take a snapshot of that particular texture ( brickwork, wood grain, concrete ) then photo the whole building as a master reference file ! thisway you wont be filling the HDD with lots of data that isnt needed and allso itll be faster loading into your photo edit program be it PSP,Photoshop or even MS Paintrgds Jeff

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Sorry for the late reply Bance and thanks for this info. It is quite pertinent. I have reproduced your 640x480 resized image above with an equal quality using PSP. But to further reduce it to a width of 512 is what has brought the image quality unusable as I mentionned in a previous post. It seams there is a limit one can resize and maintain an acceptable quality after which it degrades fast.This image I chosed, was not to be process for a scenery texture. I just got it on the net and wandered about, if I had to, to what degree I could resize it and yet keeping an acceptable quality for texture purpose. I agree with you it is quite complex for this task. When I will take my own shots, I will make shure I framed them properly for their end usage and also do it under sober enlightment ;-)Again, thanks to you and all others who also brought usefull comments. Realy appreciated.Hugo

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