Thank you for your reply, I appreciate the input! Overall I agree with what you are saying about the "bleeding obvious". However, I down scaled the exact same images on BlackBerry's and had no problems whatsoever. In our graphics arts, I downscale graphics all the time and end up with great looking images. The problem I am experiencing is something particular to Android Canvas scale and is similar to the problem in the link I posted.
In intend to have a pinch zoom control the canvas scale so it looks like I have a challenge ahead of me. One would think if I can pull it off on a BlackBerry I could do it on an Android somehow. I hope I am not stuck with it as you say. On Jan 22, 1:05 am, Peter Webb <[email protected]> wrote: > At the risk of stating the bleeding obvious, if you upscale a bitmap > *anywhere* in your code by a factor which is not an exact integer (1, > 2, 3, etc) then the system will not be able to exactly reproduce the > original image, and will be interpolating and/or duplicating pixels to > make it fit. Which gives you a not so great result. > > You have gone to great lengths to avoid scaling when you read it in > (using Bitmap Factory Options), this is largely a waste of time if you > scale it for writing using canvas.scale. You will still get scaling > artefacts on write. You need to suppress scaling for read *and* write. > > The only way that I know of to get pinsharp graphics - with your > bitmaps appearing exactly how you intended - is to write to a canvas > which has the same resolution as the actual device (or View). The > downside of this is that you have to manage all possible screen > resolutions within your code, as you can no longer use the system to > map a fixed co-ordinate space in your code to the specs of the actual > screen. A pretty obvious trade-off between coding simplicity and image > quality. > > If you are already relying on automatic output scaling for lots of > other stuff in your code, you are probably stuck with it. > > Peter Webb > > On Jan 22, 2:15 pm, JamesColeman <[email protected]> > wrote: > > > > > > > > > I am having Image Quality problems using Canvas and > > canvas.scale(Scale, Scale); they look exactly like the following: > > >http://stackoverflow.com/questions/2041207/android-quality-of-the-ima... > > > I believe I have read all the posts on image quality problems when re- > > sizing bitmaps, but it doesn't seem to help when scaling with a Canvas > > scale(float scale). > > > I have tried many different options as suggested by the image quality > > posts. > > > BitmapFactory.Options options = new BitmapFactory.Options(); > > options.inJustDecodeBounds = false; > > options.inDither = false; > > options.inSampleSize = 1; > > options.inScaled = false; > > options.inPreferredConfig = Bitmap.Config.ARGB_8888;//I thought this > > would do it > > CurrentPicture = BitmapFactory.decodeFile(path, options);//Also tried > > decodeStream() > > > PicturePaint = new Paint(); > > //PicturePaint = new Paint(Paint.FILTER_BITMAP_FLAG); //I also tried > > this > > //PicturePaint = new Paint(Paint.ANTI_ALIAS_FLAG); //I also tried > > this > > canvas.scale(Scale, Scale); > > canvas.drawBitmap(CurrentPicture, 0, 0, PicturePaint); > > > I am quite concerned as I am in serious trouble if I can't get the > > image quality problem solved. Any help is appreciated. > > > Thanks! -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
