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1bit / bitmap mode colour format?

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Goood afternoon.

   In my company i work with pictures that has 112295X13294. So there are very big files.For the moment i working with this kind of documents in Photoshop. After working a document i change it in Bitmap mode and save it in TIFF compressed file.The final size is 11 Mb files with very best quality.Thet are black&white files.

For the moment with Affinity photo i am in tested mode.And i simply can't save my final files less then 100 Mb Tiff file.

 

I am not and expert user in images but Photohop has the best results for this type of files.

I am impress of what can do Affinity and is doing the same thing that i do in Photoshop but exporting the files is th only thing for the moment that i couldn't not purchase the application.

If there is other things that i miss here in Affinity please give me feedback.

 

Thank you.

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Bitmap mode and save it in TIFF compressed file.The final size is 11 Mb files with very best quality. Thet are black&white files.

For the moment with Affinity photo i am in tested mode.And i simply can't save my final files less then 100 Mb Tiff file.

 

Problem is that AP cannot save 1-bit TIFFs. That is why size is 10 fold. AP is not suitable for 1-bit work now as there is no 1-bit work space.

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I work in book publishing and 1-bit TIFF files are essential. If you have a greyscale image, the printer's software will automatically apply a halftone screen, which degrades the image. This is really a sine qua non of a serious graphics program. PNG and GIF images are often rejected by printers. 

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11 minutes ago, peterdanckwerts said:

If you have a greyscale image, the printer's software will automatically apply a halftone screen, which degrades the image. 

 

How does a halftone screen degrade a pure black image? ears.gif


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Believe me it does. I don't pretend to know how these rasterising programs work but they seem to work on the assumption that there is no such thing as pure black or pure white in a greyscale image (a reasonable assumption). In any case, a high halftone screen resolution might be 200 dpi (many digital presses use less), a fraction of the resolution of the raster engine (or a typical 600dpi 1-bit image), so you'd end up with what was effectively a very low resolution image with jagged edges. Indeed, if you applied a screen to the text, it would look terrible.

 

There might also be cases where you are reproducing an existing halftone (say from an old book). There are two ways to avoid screen clash (the moiré pattern when two screens have been applied to an image): (1) soften the image to remove the visible screen (which will inevitable reduce image quality); or (2) reproduce dot-for-dot, where you maintain the original screen pattern. This can only be done with a 1-bit image.

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I should have added, that the halftone screen will inevitably be lower resolution than the maximum resolution of the raster engine because halftone dots are of variable size, so evey dot is made up of several scan lines. By the way, I see that Graphic Converter, which I have, can convert to 1-bit.

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Quote

How does a halftone screen degrade a pure black image?

Halftoning effectively blurs the edges of line art.

A printer (imagesetter) has a fixed resolution. All it actually print is printer spots of the same size. Printer spots are the actual hardware resolution of the imagesetter (typically 3000 or more spots per inch).

Halftone dots are made up of printer spots..Each dot in a halftone is a collection of printer spots, trying to simulate a circle..The number of different circle sizes possible is therefore determined by the number of printer spots available to simulate them. Divide the number of available printer spots (SPI) by the halftone ruling (LPI), and that's the theoretical number of different-size halftone dots (levels of grey) the device can print. That's why you always get more banding from, say, a 600 SPI laser printer than you do from a 3000 SPI imagesetter.

Everything in a greyscale image gets halftoned. That means the raster is printed as halftone dots, at the line ruling of the halftone screen (typically 150 lines per inch). It also becomes effectively anti-aliased by the halftoning.process.That's why black text that is part of a raster image looks fuzzy compared to black vector text stacked in front of a raster image.

1 bit raster objects do not get halftoned at all. They are simply "filled in" with tiny printer spots. So it's common practice to, for example, create or scan line art (think of the inking of a comic book illustration) as 1-bit rasters at something like 1200 PPI, which overlay grayscale or full color raster images. The color artwork prints as 1/150th inch halftone dots. But the 1-bit raster actually prints as 1/1200th-inch squares, giving a crisp, sharp-edged, aliased (not anti-aliased) appearance.

You can sort of think of 1-bit color depth as the "vector" version of raster imaging in that exactly what you've "drawn" simply gets "filled in" with the tiniest printer spots of the given output device. Take a look at this PDF: Zoom into it as far as you can. Tell me if you think it is raster image or a vector line.

JET

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On 22/07/2017 at 2:19 PM, JET_Affinity said:
Quote

How does a halftone screen degrade a pure black image?

Halftoning effectively blurs the edges of line art.

A printer (imagesetter) has a fixed resolution. All it actually print is printer spots of the same size. Printer spots are the actual hardware resolution of the imagesetter (typically 3000 or more spots per inch).

Halftone dots are made up of printer spots..Each dot in a halftone is a collection of printer spots, trying to simulate a circle..The number of different circle sizes possible is therefore determined by the number of printer spots available to simulate them. Divide the number of available printer spots (SPI) by the halftone ruling (LPI), and that's the theoretical number of different-size halftone dots (levels of grey) the device can print. That's why you always get more banding from, say, a 600 SPI laser printer than you do from a 3000 SPI imagesetter.

Everything in a greyscale image gets halftoned. That means the raster is printed as halftone dots, at the line ruling of the halftone screen (typically 150 lines per inch). It also becomes effectively anti-aliased by the halftoning.process.That's why black text that is part of a raster image looks fuzzy compared to black vector text stacked in front of a raster image.

1 bit raster objects do not get halftoned at all. They are simply "filled in" with tiny printer spots. So it's common practice to, for example, create or scan line art (think of the inking of a comic book illustration) as 1-bit rasters at something like 1200 PPI, which overlay grayscale or full color raster images. The color artwork prints as 1/150th inch halftone dots. But the 1-bit raster actually prints as 1/1200th-inch squares, giving a crisp, sharp-edged, aliased (not anti-aliased) appearance.

JET

 

Thanks for the comprehensive reply, JET! thumbup1.gif


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I often need to design CD packaging, including barcodes and silkscreened CD labels. 1-bit bitmap images are crucial for design jobs like these. I very much hope that the bitmap color mode will find its way to Affinity Photo in some future update. I already bought the program and I'd very much like to switch over from Photoshop, and right now it's only the bitmap issue that's holding me back.

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I encountered this limitation too. I prepare comics work for print, and for that 1bit black and white high resolution 800ppi-1200ppi images must be created.

While Photoshop has the option to work in 1bit image mode, most of the functionality is deactivated: layers do not work for example. And to composite the line art with the colour plate, InDesign is required to produce a PDF.

After some trial and error I discovered that, as far as I could find, only one non-Adobe workflow option exists. This assumes the line art is inked in B&W at a minimum of 800ppi or scanned at that minimum resolution. I tried a combination of Gimp, Scribus, but while Scribus supports export to PDFx/4 with 1bit transparent images, I couldn't create a good transparent 1200ppi 1bit image in Gimp.

So I do my prepwork in PhotoLine now, which supports 1bit image layers, and these can be combined in the same layer stack with the 300ppi colour work. First I open the 300ppi colour work, then import the 1bit 1200ppi line art, activate transparency for this layer, and remove the white background. Then I add the vector text balloons and other vector elements, and export a PDFx/3 document. PhotoLine miraculously seems to understand that I want a layered 300ppi PDF with a 1bit B&W1200ppi layer printed on top, which was unexpected when I first tried it a year ago. The result is a nice layered PDF which prints the page's colours at 300ppi, the line art superimposed at a crisp 1200ppi, and the vectors at the image setters max res.

If you need to prepare 1bit images, just get PhotoLine for this. Work in Affinity Photo, and convert to 1bit with PhotoLine, and output. I use PhotoLine as a InDesign replacement for this type of work. It's an inexpensive solution to a very particular workflow requirement.

One caveat with both Affinity Photo and PhotoLine: neither one supports an 8bit (or less) indexed image mode. For this I use Pro Motion NG - which is kinda the industry standard for indexed pixel art anyway. If I need to work on indexed images, I open the art or photo in PM, and it converts it nicely to an indexed image. And PM being a specialized indexed image editor, I get the best indexed image tools in the business. Good for textile print prep too, to get remove those anti-aliased edges :-)

So three apps: Affinity Photo, PhotoLine, and Pro Motion NG combine to achieve an even more powerful workflow with indexed and 1bit images compared to Adobe. Not bad.

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To publish comics, one needs a layer of 300dpi for colors and a layer of 1200dpi lineart, bitmap. There mustn't occur gray pixels. 

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2 more reasons why 1bit is needed:

- some type design applications only accept 1-bit clipboard content to be pasted (in the background for tracing).

- I design/produce pixel fonts and symbols for consumer products: very often in 1-bit space.

The Paint Brush and the Pixel tools should get special behavior in 1-bit mode: when starting to paint on a black pixel it should work as an eraser.

And I wish the would be a way to make straight diagonal lines drawn with these tool snap live to grid-friendly angles.

(1:1 (45 degree), 1:2, 1:3, 1:4, 1:6, 1:6) so that diagonal bitmap lines get perfect patters.

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I haven't done print work in a bit, but now that I'm working in it again I could absolutely use 1-bit TIFF in my workflow, and the absence of this is missed.

If this is seen by the devs as low-priority, I would argue additional export formats/options are pretty key to image editing software, even more important than "cool" features.

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