Unwanted outlines on 300dpi bitmap

[gwpriester]

This is nothing new but something I would like to see addressed.

When I create my stereograms for publication, I work at 300dpi, the industry standard resolution. My page size is 8" x 10" 960px X 768 My repeating panel size is 17% of the width: 163px x 768px 17 or 15% width work best for viewing. My repeating panel is positioned just off the page over the pasteboard at X -180 Y 0.

More often than not, when I create my stereogram, there is a faint outline in the repeating pattern. If my panel is black, the faint outline is more pronounced.

My work-around for this is to place a rectangle behind my repeating panel and make it the same color. (What we used to advise when working with 256 colors) and this works. For more complex panels I create a series of colored rectangles.

But all excuses aside, the bitmap creation should be more precise and not show a thin outline. Especially at 300dpi.

Acorn will say, make the panel 164px wide, Xara does better with even numbers. Egg will say to make the resolution 288px and that will solve the problem. And it does. But 300dpi is the resolution I work at. And it is the resolution my client requires. It is not negotiable.

I don't expect this ever to be fixed, just as from day one (in 1996 in my case) many of us who migrated from Corel Draw have asked for a Ctrl + R to repeat the last action.

It's just a slow day and I thought I would kavetch a bit.

[handrawn]

as i understand it the thin lines are because of anti-aliasing; working in 'full colour' view may fix that but it may also degrade your image quality if they are not pure vector

alternatively it may help if you work at 96dpi in the workspace - that is create all your images 312.5% larger than they will be when exported at 300 dpi [ratio 300:96 is 312.5%], being careful about whole pixels

[Egg Bramhill]

Can you attach a xar file that creates these outlines Gary

[gwpriester]

Can you attach a xar file that creates these outlines Gary

Not really, because the outlines are created by my stereogram software when it combines the depth map image with the repeating texture/panel.

[handrawn]

ah right... are you saying the lines are not there when you view the repeating textures in xara ?

[MarcT]

Iv'e noticed that also.

It produces less than ideal bitmap outputs and I have to potter with the files after.
In this example the shapes are exactly next to one and another.

(This example is on v11 because v19 jammed on an update, but If I remember the newer version behaves the same.)

[Acorn]

Gary, as if I would ever suggest doing evens.

I have tried a number of approaches and I cannot force a vertical gap in any.

My main suggest would be to work off a page size of 1000x800px and set your dpi to 288.
Work as normal but finally select the resultant image, which will be 800px height and lock-change the height to 768px.
The final image will be at 300dpi.

Technically the width will be 169.8px but make your shape 170x800px for convenience (evens!).
The 300dpi version will be 163.2x768px so you will have a sub-pixel overlap rather than a gap.

The fuller way to achieve fractional pixel widths and positioning is to work with SVG and embedded images.
Create a box, 163x768px.
Placeholder body:
<svg width="100%" height="100%"> <image width="163" height="768" xlink:href="index_html_files/fred.png" />
</svg>
fred is also 163x768px. fred has to be on the page (underneath or some other hiding mechanism).
I get a single artefact in Chrome and none in MS Edge up to 500% scaling.

Are you sure what you are seeing is not just failures in your graphics card and browser to fully render properly?

Acorn

[gwpriester]

These are all good suggestions. But at the end of the day, I have a method that works and I will stick with it.

As I said, I was just blowing off steam.

Thanks for your ideas and suggestions.

[handrawn]

it was a very kavetching post, if not cute already

if it helps the issue exits in other software too

a method that works is a thing to hold fast to

[Acorn]

Iv'e noticed that also.

It produces less than ideal bitmap outputs and I have to potter with the files after.
In this example the shapes are exactly next to one and another.

(This example is on v11 because v19 jammed on an update, but If I remember the newer version behaves the same.)

Marc, this is where the benefits of SVG shine. All your shapes would be rendered as SVG Paths and as such are more accurate that PNG positioning.

I assume your performed Combine Shape > Intersect All Shapes?
My design page then shows a very faint slice line that grows no wider up to max zoom.
When rendered the browser shows the cuts more roughly and the edges more around when scaling.

I cheated by adding some CSS:
<style>
.edging {
transform: scale(1.018);
}
</style>

The proper way to do it is to apply the feMorphology Filter Primitive, using a filter SVG:
<svg>
<filter id="blur">
<feMorphology in="SourceGraphic" operator="dilate" radius="0.5">
</feMorphology>
</filter>
</svg>

and applying some CSS to all the shapes as filter: url(#blur);.

Acorn