6 Replies Latest reply on Aug 6, 2017 3:51 PM by JagMaker

    Photoshop, GrayScale, and 20000 pieces


      hello!, I would like to ask the specialists who have an experience with large images


      I make a square image based on 20,000 small pictures (big map with objects), each one has a grayscale-8 conversion and .png format

      At the end I get an image of ~ 61000 * 61000px, it's pretty big and have weight of 25.5 gb


      so, i want to ask, how can i reduce final weight without loss of quality?


      sure, i can reduce it size twice, but it will reduce quality, so dont wanna

      also i can save it as .DDS or .TIFF.,i don't care of any mipmaps or alpha channels., and dont know what to chose, dxt1 or this tiff =/

      also i can to 'batch convert' 20000 pieces to something else, with light weight,

      but here i need ur advice)

        • 1. Re: Photoshop, GrayScale, and 20000 pieces
          rayek.elfin Level 4

          Depends on your output. What are you planning to use this for? Print? Web? Large banner? etc.


          Is each small part a smart object with a larger than required resolution? Rasterize each smart object in that case. (in Layer-->Rasterize-->All Layers)

          • 2. Re: Photoshop, GrayScale, and 20000 pieces
            davescm Adobe Community Professional


            If you are saving the master copy - don't reduce it, don't rasterize - just save as a *.psb complete with layers, smart objects  etc. Disk space is relatively cheap - the ability to go back and edit a master file later - priceless. That said you can enable compression on the psb file in Preferences > File Handling and uncheck "Disable Compression of PSD and PSB Files". The compression is lossless and will reduce file size but at the expense of loading time.


            If you are sending the file on - then send the minimum needed for that purpose. If no further editing will be done then flattening a copy will reduce file size considerably and you can  again look at the compression options under the various file types



            1 person found this helpful
            • 3. Re: Photoshop, GrayScale, and 20000 pieces
              JagMaker Level 1

              It will be an exterior map for PC game, made with same method as google maps)

              I want to note, it is not necessary that image must be .dds format (because it 2d image, big, flat and work in game as it is)

              But the photoshop allows me to choose only between .tiff or .dds, which one have less weight?


              No, each small picture - is a layer. Full image is 141*141 layers, each layer over 430*430px size, it completely gray, have 8 bit channel, and .png format.

              so, maby there is some lower formats or channels i can use to reduce it's weight?

              • 4. Re: Photoshop, GrayScale, and 20000 pieces
                JagMaker Level 1

                ty Dave, i'm already have saved .psb file) time of loading anyway will be long, because each piece as layer taking ~1.5mb RAM (1.5*20000 = 30gb ), and i can't merge them, because I will lose the possibility to edit each layer individually)


                Yep, i'm looking for minimum needed), didn't know about flattering, ty, will try it

                • 5. Re: Photoshop, GrayScale, and 20000 pieces
                  davescm Adobe Community Professional


                  Don't flatten the master - or you will lose the ability to edit !

                  Only flatten the copy

                  • 6. Re: Photoshop, GrayScale, and 20000 pieces
                    JagMaker Level 1

                    kk, let's play with formats and mathematics)

                    i have small .png image, gray-colored, size - 448kb.

                    if i save it as:


                    monocrome - quality completely lost, size 37.5kb = 1194.67 % win

                    16bit color - quality lost, size 150kb = 298.67 % win

                    256bit color - adds blue/yellow artifacts, size 301kb = 148.84 % win

                    24 depth - no visible changes, size 900kb = 49.78 % lose

                    JPEG - no visible changes, size 170kb = 263.53 % win (ave!)

                    gif - quality lost, size 122kb = 367.21 % win

                    tif - minor quality lost, size 516kb = 86.82 % lose

                    png - resave without alpha chanel, size 402kb = 111.44 % win


                    so, JPEG win

                    this way if i convert all 20000 pieces in jpeg, global image will be

                    25500mb (25.5gb) / 263% = 9695mb (9.6 gb)


                    not bad, but i need to reduce it more)