bitmap in silkscreen

[stressed_user]

I had a strange phenomenon lately...

I added a bitmap (monochrome, etc..) to my silkscreen and the text appeared correctly on the silk when I received the prototypes.

That was my customers logo (the most important on the board...)

I have made minor changes  (just a few rtracks) to the board, and made new gerber data.

now when I received the first production , the logo is repalced by a large black square.

So i did some tests:

-if you put the bitmap on the board, and export without closing, then the logo shows on the gerber. (looking with GCprevue)

-then close and reopen the ewprj file, and export again: the logo has dissapeared and is replaced by a large black square...

To make it more odd, the size of the silkscreen gerber file (RS274X) is five times larger than the one saved before closing the project...

This looks like a bug to me... 

Have a nice weekend

Johan

[ThiCop]

Hello Johan,

I have some questions:

Which version of Ultiboard are you using?

Are you importing monochrome bitmaps?

In Ultiboard 11 I could produce a similar "problem" when using color bitmaps.

The "import bitmap" feature is as far as I know currently only supported for monochrome bitmaps, so you should use that type of bmp files.

[stressed_user]

Thierry,

I am using Ultiboard 10.01 and 10.1

I knew that about the color bmp... 

I have converted the original logo to a monochrome bitmap, and it is 200*210 pixels. (6 kb file)

Anyway, I'm glad I found how this black square was produced...

Until now I had no idea how it happened

Maybe this may be a hint for the NI Ultiboard programmers/support people::

I remarked that when I first put the Logo, it appears on the screen in the silkscreen color (light blue)

after closing an re-opening , it appears in white...

Now, I have rebuilt this customers logo, usiing polygons and text-tricks...

I seems Ok, even after opening/closing the file.

but it is easier when I can simply import a bitmap...

especially with sophisticated logo's

Johan

[ThiCop]

Hello Johan,

In Ultiboard 11 your "bug" does not appear. You only get a "black square" when you import the wrong (color) type of bitmap.

When using the monochrome bitmap there are no problems in the new version.

[stressed_user]

Thierry,

Can you check sometjing?

When you import a bitmap of a few kbyte, how large is your silkscreen file in 274X gerber?

Best regards

Johan

[ThiCop]

Hello Johan,

I tested it and the resulting silkscreen Gerber file is indeed bigger.

I'll look further into the possible reasons for this, but I assume it has to do with the conversion to the Gerber file.

[ThiCop]

Hello,

Sorry for the late feedback.

The "problem" is indeed in the conversion to the gerber file.The file format itself is totally different from a bmp-file.

Basically Gerber file tells the machine do this; go to coordinate xy to start drawing a line to another coordinate xy then stop, next go to a new coordinate and start to draw line again. This is totally different from what a bitmap does: mapping every pixel in your bitmap-"picture".