Prime pix & tutorial on avoiding streaks

[Joe Horn]

I enjoy showing off my HP Prime displaying full-screen images, such as these:



For those who like doing the same, I've uploaded a gallery of 138 good 320×240 images, along with all the HPPRGM programs which display them on the Prime.

Prime often displays ugly streaks in areas that should be smooth. I've also uploaded a tutorial about what causes these streaks and how to avoid them.

Enjoy!

[Han]

Great gallery and very informative regarding streaks. Thanks for sharing!

[Tim Wessman]

To whom does that "touchably smooth knee" belong? ;-)

[Joe Horn]

(01-08-2014 09:34 PM)Tim Wessman Wrote:  To whom does that "touchably smooth knee" belong? ;-)

I wish I knew.

[Eddie W. Shore]

Amazing pics Joe! I got to try this myself.

[Jim Horn]

The banding is related to Mach Bands (not a musical group) as has been dealt with in computer graphics since the stone age. Great examples!

[eried]

Very nice gallery. I am impressed how noticeable is this bit limitation in the Sky/Pacific sea image you show as example in your webpage. Now the question is if this is a limitation in DIMGROB_P or in the calculator 'graphical system' (PIXEL_P accepts 8 bit R,G,B values).

I tried to improve that sea image via code without success (to get an automated conversion rather than using an editor, then the image converter, then sending the code), probably the image editor is doing something a bit more advanced than simple dithering.

I added all the dithering options Windows GDI+ v1.1 provides (Vista or newer) related to ARGB1555 conversions to my little app, but the result is usually better doing your process with the image editor (... in other hand, sometimes it's good to have 1 click away images ):

[Eddie W. Shore]

Saving the picture in PNG does wonders. How many pictures are we able to store on the calculator?

   

These are my dogs (my family's dogs): Molly is on the left, Lilly is one the right.

   

[eried]

(01-12-2014 10:59 PM)Eddie W. Shore Wrote:  How many pictures are we able to store on the calculator?

After a couple my calc get unresponsive and it reboots, around 12-15 but in theory calculator has 256 MB of flash, with about 100-150 MB free to hold ~120 (320x240 dimgrobbed) images.

[Mic]

Nice pics.

[cyrille de brébisson]

Hello

(01-11-2014 12:53 AM)eried Wrote:  Very nice gallery. I am impressed how noticeable is this bit limitation in the Sky/Pacific sea image you show as example in your webpage. Now the question is if this is a limitation in DIMGROB_P or in the calculator 'graphical system' (PIXEL_P accepts 8 bit R,G,B values).

If you think about it, 32K colors sounds like a LOT!
however, if you are only playing on one color plane (let us say blue, for sky), and then only using a small band of it (like 50% of the possible choices because you do not go to full blue, no do you go to full white), with 5 bits, this leaves you with only 16 colors to play with... ie, 16 bands...

32K colors was chosen because:
- well, who needs more on a calculator (obviously, everyone!)
- It reduces memory use, in turn, this reduced RAM and CPU useage to manage the extra RAM. It also reduces power consumption as only 1/2 as much memory as a 16M color system would need to handle.

At the moment, graphic system, in Idle needs to process 320*240*2(bytes per pixel)*60(hz) bytes per second = 9MB!
moving to a true color would need 18MB of bandwidth per second...

Cyrille

[Joe Horn]

A new page (Page Zero) has been added to the Prime Pix gallery. These 24 fun new pix are dedicated to the brainiacs of MoHPC (that's YOU!). Enjoy!
http://holyjoe.net/Prime/Pix/page0.htm