So I'm trying to knock down the graphic size for my adventure, and when I do the resulting pics look a little too small and fuzzy. Is there a good way to reduce a picture's file size without loss of image resolution?
Thanks.
Thanks.
Reducing picture size
- Thread starter Blue Ghost
- Start date
Reduce color.
Crop out unimportant parts. For many formats, widths that are powers of 2 or multiples of 8 give more optimal results.
Don't forget to disable transparency if the format you are using supports it and you don't need it.
On a Windows PC - IrfanView is well featured for this work.
Best results are often achieved by first tweaking the original color - using histograms and color range replacement. Lots of shades of one unimportant color vs few shades of a more important, but less pixel count, color can be manually tweaked (like a red highlight line vs a blue sky).
Crop out unimportant parts. For many formats, widths that are powers of 2 or multiples of 8 give more optimal results.
Don't forget to disable transparency if the format you are using supports it and you don't need it.
On a Windows PC - IrfanView is well featured for this work.
Best bet? Do the art in a vector program, not a raster one. Inkscape, Illustrator, or Freehand are the big three.
http://www.maa.org/editorial/mathgames/mathgames_08_01_05.html
For inclusion in Acrobat PDF files, you have several options for getting them in, not the least expensive being importing in Acrobat Pro. Apple Pages will take EPS files (a raster format) and output them in a PDF export as vector images within the PDF.
No matter the magnification, Vector images remain crisp; they only get blurry when you shrink them too far, as the lines merge together.
Andrew Boulton
The Adminator
What format are they? PNG compresses well; if you're careful you can get JPGs smaller, but they tend to get fuzzy.
That's helping, but reducing the image to a black and white pic seems to do it little justice. How is it that other PDF files have full color covers, but only weigh in at a couple hundred kilobytes.
Foremost - for purposes of compression - not all images are created equal and neither are all compression programs.
Keep in mind - JPEG and the like are 'standards' - that means while the final product is interchangeable, different programs can yield different results visually and in size.
Unless it is an illustration - black and white will gain little, at significant visual loss, when using most lossy compression formats. If it is an illustration - vector is generally the way to go... though that runs into skill and/or quality of tracing issues.
For PDF and file size, hand coded postscript ultimately offers the very best possible 'compression'. But again, a skill issue (and possibly time).
By 'reducing color' I mean not just 'bits', but the number of unique colors in the image. For instance, most black backgrounds and sky blues have large regions of color that have lots of unique, but non-visible color values that could all be changed to a single color. Specifically reducing 'luma' can result in even better results, but that is a bit too complicated/uncommon to address in here. Reducing unique color count will have a related impact (to luma).
Formats like JPEG 'weigh' colors with the knowledge that the human eye is more sensitive to some colors than others as will as to intensity over color.
Turning off color (chroma) subsampling can result in a better quality image (and sometimes even marginally reduce size). Irfanview, IIRC, has this option.
I'm trying to keep this simple - sorry when it flys overhead, or oversimplifies - but compression and color science are complex (and intertwined) arts.
Pictures - continuous tone images such as photographs and renderings - compress, well or not, depending on colors present and closeness of similar and contrasting colors to each other. Pictures that contain sharp contrast - straight edges delineating features and drastic hue changes, like red tissue falling in front a blue pond surrounded by green grass - will exhibit various 'artifacts'. Especially 'blocking' and strange banding of color or dot like halos.
Computer created (rendered and rasterized vector) images can often suffer from such. Basically the less 'crisp' the image the better the look from JPEG and similar lossy compression formats. Blurring (and special jittering) before compression can improve the final look.
Generally, for a better JPEG - use a much higher image resolution (more dots) and 'filter' the image. Start by reducing color. Then reduce the size using a Lanczos filter (this will 'blur' the image and reduce contrast). Then reduce the color again. Then save in a compressed format - trying different widths (and even heights), specifically in whole multiples of 8.
When 'reducing color' - do so depending on what colors are most important and with knowledge of the RGB curves (or YCbCr if available). This is not just, or even mostly, about reducing bits! If you look at a histogram - you want fewer individual spikes (while still having a pleasing look).
Keep in mind - JPEG and the like are 'standards' - that means while the final product is interchangeable, different programs can yield different results visually and in size.
Unless it is an illustration - black and white will gain little, at significant visual loss, when using most lossy compression formats. If it is an illustration - vector is generally the way to go... though that runs into skill and/or quality of tracing issues.
For PDF and file size, hand coded postscript ultimately offers the very best possible 'compression'. But again, a skill issue (and possibly time).
By 'reducing color' I mean not just 'bits', but the number of unique colors in the image. For instance, most black backgrounds and sky blues have large regions of color that have lots of unique, but non-visible color values that could all be changed to a single color. Specifically reducing 'luma' can result in even better results, but that is a bit too complicated/uncommon to address in here. Reducing unique color count will have a related impact (to luma).
Formats like JPEG 'weigh' colors with the knowledge that the human eye is more sensitive to some colors than others as will as to intensity over color.
Turning off color (chroma) subsampling can result in a better quality image (and sometimes even marginally reduce size). Irfanview, IIRC, has this option.
I'm trying to keep this simple - sorry when it flys overhead, or oversimplifies - but compression and color science are complex (and intertwined) arts.
Pictures - continuous tone images such as photographs and renderings - compress, well or not, depending on colors present and closeness of similar and contrasting colors to each other. Pictures that contain sharp contrast - straight edges delineating features and drastic hue changes, like red tissue falling in front a blue pond surrounded by green grass - will exhibit various 'artifacts'. Especially 'blocking' and strange banding of color or dot like halos.
Computer created (rendered and rasterized vector) images can often suffer from such. Basically the less 'crisp' the image the better the look from JPEG and similar lossy compression formats. Blurring (and special jittering) before compression can improve the final look.
Generally, for a better JPEG - use a much higher image resolution (more dots) and 'filter' the image. Start by reducing color. Then reduce the size using a Lanczos filter (this will 'blur' the image and reduce contrast). Then reduce the color again. Then save in a compressed format - trying different widths (and even heights), specifically in whole multiples of 8.
When 'reducing color' - do so depending on what colors are most important and with knowledge of the RGB curves (or YCbCr if available). This is not just, or even mostly, about reducing bits! If you look at a histogram - you want fewer individual spikes (while still having a pleasing look).
Grrr... I tried compressing the original JPEGs that Wayne sent me, and instead of 3 or 4 MBs, they're now 1.5MBs.
Whoever heard of a 10MB PDF for an adventure?
This is really frustrating, but I'm a patient man. I'll let Wayne give me the lo-down before I start screwing around with the pics again.
Whoever heard of a 10MB PDF for an adventure?
This is really frustrating, but I'm a patient man. I'll let Wayne give me the lo-down before I start screwing around with the pics again.
o:
